// valarray
// #include
// #include
// #include
// #include
// #include
namespace nlohmann
{
namespace detail
{
template
void from_json(const BasicJsonType& j, typename std::nullptr_t& n)
{
if (JSON_UNLIKELY(not j.is_null()))
{
JSON_THROW(type_error::create(302, “type must be null, but is ” + std::string(j.type_name())));
}
n = nullptr;
}
// overloads for basic_json template parameters
template::value and
not std::is_same::value,
int> = 0>
void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val)
{
switch (static_cast(j))
{
case value_t::number_unsigned:
{
val = static_cast(*j.template get_ptr());
break;
}
case value_t::number_integer:
{
val = static_cast(*j.template get_ptr());
break;
}
case value_t::number_float:
{
val = static_cast(*j.template get_ptr());
break;
}
default:
JSON_THROW(type_error::create(302, “type must be number, but is ” + std::string(j.type_name())));
}
}
template
void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b)
{
if (JSON_UNLIKELY(not j.is_boolean()))
{
JSON_THROW(type_error::create(302, “type must be boolean, but is ” + std::string(j.type_name())));
}
b = *j.template get_ptr();
}
template
void from_json(const BasicJsonType& j, typename BasicJsonType::string_t& s)
{
if (JSON_UNLIKELY(not j.is_string()))
{
JSON_THROW(type_error::create(302, “type must be string, but is ” + std::string(j.type_name())));
}
s = *j.template get_ptr();
}
template <
typename BasicJsonType, typename ConstructibleStringType,
enable_if_t <
is_constructible_string_type::value and
not std::is_same::value,
int > = 0 >
void from_json(const BasicJsonType& j, ConstructibleStringType& s)
{
if (JSON_UNLIKELY(not j.is_string()))
{
JSON_THROW(type_error::create(302, “type must be string, but is ” + std::string(j.type_name())));
}
s = *j.template get_ptr();
}
template
void from_json(const BasicJsonType& j, typename BasicJsonType::number_float_t& val)
{
get_arithmetic_value(j, val);
}
template
void from_json(const BasicJsonType& j, typename BasicJsonType::number_unsigned_t& val)
{
get_arithmetic_value(j, val);
}
template
void from_json(const BasicJsonType& j, typename BasicJsonType::number_integer_t& val)
{
get_arithmetic_value(j, val);
}
template::value, int> = 0>
void from_json(const BasicJsonType& j, EnumType& e)
{
typename std::underlying_type::type val;
get_arithmetic_value(j, val);
e = static_cast(val);
}
// forward_list doesn’t have an insert method
template::value, int> = 0>
void from_json(const BasicJsonType& j, std::forward_list& l)
{
if (JSON_UNLIKELY(not j.is_array()))
{
JSON_THROW(type_error::create(302, “type must be array, but is ” + std::string(j.type_name())));
}
std::transform(j.rbegin(), j.rend(),
std::front_inserter(l), [](const BasicJsonType & i)
{
return i.template get();
});
}
// valarray doesn’t have an insert method
template::value, int> = 0>
void from_json(const BasicJsonType& j, std::valarray& l)
{
if (JSON_UNLIKELY(not j.is_array()))
{
JSON_THROW(type_error::create(302, “type must be array, but is ” + std::string(j.type_name())));
}
l.resize(j.size());
std::copy(j.m_value.array->begin(), j.m_value.array->end(), std::begin(l));
}
template
void from_json_array_impl(const BasicJsonType& j, typename BasicJsonType::array_t& arr, priority_tag<3> /*unused*/)
{
arr = *j.template get_ptr();
}
template
auto from_json_array_impl(const BasicJsonType& j, std::array& arr,
priority_tag<2> /*unused*/)
-> decltype(j.template get(), void())
{
for (std::size_t i = 0; i < N; ++i)
{
arr[i] = j.at(i).template get();
}
}
template
auto from_json_array_impl(const BasicJsonType& j, ConstructibleArrayType& arr, priority_tag<1> /*unused*/)
-> decltype(
arr.reserve(std::declval()),
j.template get(),
void())
{
using std::end;
arr.reserve(j.size());
std::transform(j.begin(), j.end(),
std::inserter(arr, end(arr)), [](const BasicJsonType & i)
{
// get() returns *this, this won’t call a from_json
// method when value_type is BasicJsonType
return i.template get();
});
}
template
void from_json_array_impl(const BasicJsonType& j, ConstructibleArrayType& arr,
priority_tag<0> /*unused*/)
{
using std::end;
std::transform(
j.begin(), j.end(), std::inserter(arr, end(arr)),
[](const BasicJsonType & i)
{
// get() returns *this, this won’t call a from_json
// method when value_type is BasicJsonType
return i.template get();
});
}
template ::value and
not is_constructible_object_type::value and
not is_constructible_string_type::value and
not is_basic_json::value,
int > = 0 >
auto from_json(const BasicJsonType& j, ConstructibleArrayType& arr)
-> decltype(from_json_array_impl(j, arr, priority_tag<3> {}),
j.template get(),
void())
{
if (JSON_UNLIKELY(not j.is_array()))
{
JSON_THROW(type_error::create(302, “type must be array, but is ” +
std::string(j.type_name())));
}
from_json_array_impl(j, arr, priority_tag<3> {});
}
template::value, int> = 0>
void from_json(const BasicJsonType& j, ConstructibleObjectType& obj)
{
if (JSON_UNLIKELY(not j.is_object()))
{
JSON_THROW(type_error::create(302, “type must be object, but is ” + std::string(j.type_name())));
}
auto inner_object = j.template get_ptr();
using value_type = typename ConstructibleObjectType::value_type;
std::transform(
inner_object->begin(), inner_object->end(),
std::inserter(obj, obj.begin()),
[](typename BasicJsonType::object_t::value_type const & p)
{
return value_type(p.first, p.second.template get());
});
}
// overload for arithmetic types, not chosen for basic_json template arguments
// (BooleanType, etc..); note: Is it really necessary to provide explicit
// overloads for boolean_t etc. in case of a custom BooleanType which is not
// an arithmetic type?
template::value and
not std::is_same::value and
not std::is_same::value and
not std::is_same::value and
not std::is_same::value,
int> = 0>
void from_json(const BasicJsonType& j, ArithmeticType& val)
{
switch (static_cast(j))
{
case value_t::number_unsigned:
{
val = static_cast(*j.template get_ptr());
break;
}
case value_t::number_integer:
{
val = static_cast(*j.template get_ptr());
break;
}
case value_t::number_float:
{
val = static_cast(*j.template get_ptr());
break;
}
case value_t::boolean:
{
val = static_cast(*j.template get_ptr());
break;
}
default:
JSON_THROW(type_error::create(302, “type must be number, but is ” + std::string(j.type_name())));
}
}
template
void from_json(const BasicJsonType& j, std::pair& p)
{
p = {j.at(0).template get(), j.at(1).template get()};
}
template
void from_json_tuple_impl(const BasicJsonType& j, Tuple& t, index_sequence /*unused*/)
{
t = std::make_tuple(j.at(Idx).template get::type>()…);
}
template
void from_json(const BasicJsonType& j, std::tuple& t)
{
from_json_tuple_impl(j, t, index_sequence_for {});
}
template ::value>>
void from_json(const BasicJsonType& j, std::map& m)
{
if (JSON_UNLIKELY(not j.is_array()))
{
JSON_THROW(type_error::create(302, “type must be array, but is ” + std::string(j.type_name())));
}
for (const auto& p : j)
{
if (JSON_UNLIKELY(not p.is_array()))
{
JSON_THROW(type_error::create(302, “type must be array, but is ” + std::string(p.type_name())));
}
m.emplace(p.at(0).template get(), p.at(1).template get());
}
}
template ::value>>
void from_json(const BasicJsonType& j, std::unordered_map& m)
{
if (JSON_UNLIKELY(not j.is_array()))
{
JSON_THROW(type_error::create(302, “type must be array, but is ” + std::string(j.type_name())));
}
for (const auto& p : j)
{
if (JSON_UNLIKELY(not p.is_array()))
{
JSON_THROW(type_error::create(302, “type must be array, but is ” + std::string(p.type_name())));
}
m.emplace(p.at(0).template get(), p.at(1).template get());
}
}
struct from_json_fn
{
template
auto operator()(const BasicJsonType& j, T& val) const
noexcept(noexcept(from_json(j, val)))
-> decltype(from_json(j, val), void())
{
return from_json(j, val);
}
};
} // namespace detail
/// namespace to hold default `from_json` function
/// to see why this is required:
/// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4381.html
namespace
{
constexpr const auto& from_json = detail::static_const::value;
} // namespace
} // namespace nlohmann
// #include
#include // or, and, not
#include // begin, end
#include // tuple, get
#include // is_same, is_constructible, is_floating_point, is_enum, underlying_type
#include // move, forward, declval, pair
#include // valarray
#include // vector
// #include
// #include
// #include
// #include
#include // size_t
#include // string, to_string
#include // input_iterator_tag
#include // tuple_size, get, tuple_element
// #include
// #include
namespace nlohmann
{
namespace detail
{
template class iteration_proxy_value
{
public:
using difference_type = std::ptrdiff_t;
using value_type = iteration_proxy_value;
using pointer = value_type * ;
using reference = value_type & ;
using iterator_category = std::input_iterator_tag;
private:
/// the iterator
IteratorType anchor;
/// an index for arrays (used to create key names)
std::size_t array_index = 0;
/// last stringified array index
mutable std::size_t array_index_last = 0;
/// a string representation of the array index
mutable std::string array_index_str = “0”;
/// an empty string (to return a reference for primitive values)
const std::string empty_str = “”;
public:
explicit iteration_proxy_value(IteratorType it) noexcept : anchor(it) {}
/// dereference operator (needed for range-based for)
iteration_proxy_value& operator*()
{
return *this;
}
/// increment operator (needed for range-based for)
iteration_proxy_value& operator++()
{
++anchor;
++array_index;
return *this;
}
/// equality operator (needed for InputIterator)
bool operator==(const iteration_proxy_value& o) const
{
return anchor == o.anchor;
}
/// inequality operator (needed for range-based for)
bool operator!=(const iteration_proxy_value& o) const
{
return anchor != o.anchor;
}
/// return key of the iterator
const std::string& key() const
{
assert(anchor.m_object != nullptr);
switch (anchor.m_object->type())
{
// use integer array index as key
case value_t::array:
{
if (array_index != array_index_last)
{
array_index_str = std::to_string(array_index);
array_index_last = array_index;
}
return array_index_str;
}
// use key from the object
case value_t::object:
return anchor.key();
// use an empty key for all primitive types
default:
return empty_str;
}
}
/// return value of the iterator
typename IteratorType::reference value() const
{
return anchor.value();
}
};
/// proxy class for the items() function
template class iteration_proxy
{
private:
/// the container to iterate
typename IteratorType::reference container;
public:
/// construct iteration proxy from a container
explicit iteration_proxy(typename IteratorType::reference cont) noexcept
: container(cont) {}
/// return iterator begin (needed for range-based for)
iteration_proxy_value begin() noexcept
{
return iteration_proxy_value(container.begin());
}
/// return iterator end (needed for range-based for)
iteration_proxy_value end() noexcept
{
return iteration_proxy_value(container.end());
}
};
// Structured Bindings Support
// For further reference see https://blog.tartanllama.xyz/structured-bindings/
// And see https://github.com/nlohmann/json/pull/1391
template = 0>
auto get(const nlohmann::detail::iteration_proxy_value& i) -> decltype(i.key())
{
return i.key();
}
// Structured Bindings Support
// For further reference see https://blog.tartanllama.xyz/structured-bindings/
// And see https://github.com/nlohmann/json/pull/1391
template = 0>
auto get(const nlohmann::detail::iteration_proxy_value& i) -> decltype(i.value())
{
return i.value();
}
} // namespace detail
} // namespace nlohmann
// The Addition to the STD Namespace is required to add
// Structured Bindings Support to the iteration_proxy_value class
// For further reference see https://blog.tartanllama.xyz/structured-bindings/
// And see https://github.com/nlohmann/json/pull/1391
namespace std
{
template
class tuple_size<::nlohmann::detail::iteration_proxy_value>
: public std::integral_constant {};
template
class tuple_element>
{
public:
using type = decltype(
get(std::declval <
::nlohmann::detail::iteration_proxy_value> ()));
};
}
namespace nlohmann
{
namespace detail
{
//////////////////
// constructors //
//////////////////
template struct external_constructor;
template<>
struct external_constructor
{
template
static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept
{
j.m_type = value_t::boolean;
j.m_value = b;
j.assert_invariant();
}
};
template<>
struct external_constructor
{
template
static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s)
{
j.m_type = value_t::string;
j.m_value = s;
j.assert_invariant();
}
template
static void construct(BasicJsonType& j, typename BasicJsonType::string_t&& s)
{
j.m_type = value_t::string;
j.m_value = std::move(s);
j.assert_invariant();
}
template::value,
int> = 0>
static void construct(BasicJsonType& j, const CompatibleStringType& str)
{
j.m_type = value_t::string;
j.m_value.string = j.template create(str);
j.assert_invariant();
}
};
template<>
struct external_constructor
{
template
static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept
{
j.m_type = value_t::number_float;
j.m_value = val;
j.assert_invariant();
}
};
template<>
struct external_constructor
{
template
static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept
{
j.m_type = value_t::number_unsigned;
j.m_value = val;
j.assert_invariant();
}
};
template<>
struct external_constructor
{
template
static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept
{
j.m_type = value_t::number_integer;
j.m_value = val;
j.assert_invariant();
}
};
template<>
struct external_constructor
{
template
static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr)
{
j.m_type = value_t::array;
j.m_value = arr;
j.assert_invariant();
}
template
static void construct(BasicJsonType& j, typename BasicJsonType::array_t&& arr)
{
j.m_type = value_t::array;
j.m_value = std::move(arr);
j.assert_invariant();
}
template::value,
int> = 0>
static void construct(BasicJsonType& j, const CompatibleArrayType& arr)
{
using std::begin;
using std::end;
j.m_type = value_t::array;
j.m_value.array = j.template create(begin(arr), end(arr));
j.assert_invariant();
}
template
static void construct(BasicJsonType& j, const std::vector& arr)
{
j.m_type = value_t::array;
j.m_value = value_t::array;
j.m_value.array->reserve(arr.size());
for (const bool x : arr)
{
j.m_value.array->push_back(x);
}
j.assert_invariant();
}
template::value, int> = 0>
static void construct(BasicJsonType& j, const std::valarray& arr)
{
j.m_type = value_t::array;
j.m_value = value_t::array;
j.m_value.array->resize(arr.size());
std::copy(std::begin(arr), std::end(arr), j.m_value.array->begin());
j.assert_invariant();
}
};
template<>
struct external_constructor
{
template
static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj)
{
j.m_type = value_t::object;
j.m_value = obj;
j.assert_invariant();
}
template
static void construct(BasicJsonType& j, typename BasicJsonType::object_t&& obj)
{
j.m_type = value_t::object;
j.m_value = std::move(obj);
j.assert_invariant();
}
template::value, int> = 0>
static void construct(BasicJsonType& j, const CompatibleObjectType& obj)
{
using std::begin;
using std::end;
j.m_type = value_t::object;
j.m_value.object = j.template create(begin(obj), end(obj));
j.assert_invariant();
}
};
/////////////
// to_json //
/////////////
template::value, int> = 0>
void to_json(BasicJsonType& j, T b) noexcept
{
external_constructor::construct(j, b);
}
template::value, int> = 0>
void to_json(BasicJsonType& j, const CompatibleString& s)
{
external_constructor::construct(j, s);
}
template
void to_json(BasicJsonType& j, typename BasicJsonType::string_t&& s)
{
external_constructor::construct(j, std::move(s));
}
template::value, int> = 0>
void to_json(BasicJsonType& j, FloatType val) noexcept
{
external_constructor::construct(j, static_cast(val));
}
template::value, int> = 0>
void to_json(BasicJsonType& j, CompatibleNumberUnsignedType val) noexcept
{
external_constructor::construct(j, static_cast(val));
}
template::value, int> = 0>
void to_json(BasicJsonType& j, CompatibleNumberIntegerType val) noexcept
{
external_constructor::construct(j, static_cast(val));
}
template::value, int> = 0>
void to_json(BasicJsonType& j, EnumType e) noexcept
{
using underlying_type = typename std::underlying_type::type;
external_constructor::construct(j, static_cast(e));
}
template
void to_json(BasicJsonType& j, const std::vector& e)
{
external_constructor::construct(j, e);
}
template ::value and
not is_compatible_object_type<
BasicJsonType, CompatibleArrayType>::value and
not is_compatible_string_type::value and
not is_basic_json::value,
int> = 0>
void to_json(BasicJsonType& j, const CompatibleArrayType& arr)
{
external_constructor::construct(j, arr);
}
template::value, int> = 0>
void to_json(BasicJsonType& j, const std::valarray& arr)
{
external_constructor::construct(j, std::move(arr));
}
template
void to_json(BasicJsonType& j, typename BasicJsonType::array_t&& arr)
{
external_constructor::construct(j, std::move(arr));
}
template::value and not is_basic_json::value, int> = 0>
void to_json(BasicJsonType& j, const CompatibleObjectType& obj)
{
external_constructor::construct(j, obj);
}
template
void to_json(BasicJsonType& j, typename BasicJsonType::object_t&& obj)
{
external_constructor::construct(j, std::move(obj));
}
template <
typename BasicJsonType, typename T, std::size_t N,
enable_if_t::value,
int> = 0 >
void to_json(BasicJsonType& j, const T(&arr)[N])
{
external_constructor::construct(j, arr);
}
template
void to_json(BasicJsonType& j, const std::pair& p)
{
j = { p.first, p.second };
}
// for https://github.com/nlohmann/json/pull/1134
template < typename BasicJsonType, typename T,
enable_if_t>::value, int> = 0>
void to_json(BasicJsonType& j, const T& b)
{
j = { {b.key(), b.value()} };
}
template
void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence /*unused*/)
{
j = { std::get(t)… };
}
template
void to_json(BasicJsonType& j, const std::tuple& t)
{
to_json_tuple_impl(j, t, index_sequence_for {});
}
struct to_json_fn
{
template
auto operator()(BasicJsonType& j, T&& val) const noexcept(noexcept(to_json(j, std::forward(val))))
-> decltype(to_json(j, std::forward(val)), void())
{
return to_json(j, std::forward(val));
}
};
} // namespace detail
/// namespace to hold default `to_json` function
namespace
{
constexpr const auto& to_json = detail::static_const::value;
} // namespace
} // namespace nlohmann
// #include
#include // assert
#include // size_t
#include // strlen
#include // istream
#include // begin, end, iterator_traits, random_access_iterator_tag, distance, next
#include // shared_ptr, make_shared, addressof
#include // accumulate
#include // string, char_traits
#include // enable_if, is_base_of, is_pointer, is_integral, remove_pointer
#include // pair, declval
#include //FILE *
// #include
// #include
namespace nlohmann
{
namespace detail
{
/// the supported input formats
enum class input_format_t { json, cbor, msgpack, ubjson, bson };
////////////////////
// input adapters //
////////////////////
/*!
@brief abstract input adapter interface
Produces a stream of std::char_traits::int_type characters from a
std::istream, a buffer, or some other input type. Accepts the return of
exactly one non-EOF character for future input. The int_type characters
returned consist of all valid char values as positive values (typically
unsigned char), plus an EOF value outside that range, specified by the value
of the function std::char_traits::eof(). This value is typically -1, but
could be any arbitrary value which is not a valid char value.
*/
struct input_adapter_protocol
{
/// get a character [0,255] or std::char_traits::eof().
virtual std::char_traits::int_type get_character() = 0;
virtual ~input_adapter_protocol() = default;
};
/// a type to simplify interfaces
using input_adapter_t = std::shared_ptr;
/*!
Input adapter for stdio file access. This adapter read only 1 byte and do not use any
buffer. This adapter is a very low level adapter.
*/
class file_input_adapter : public input_adapter_protocol
{
public:
explicit file_input_adapter(std::FILE* f) noexcept
: m_file(f)
{}
std::char_traits::int_type get_character() noexcept override
{
return std::fgetc(m_file);
}
private:
/// the file pointer to read from
std::FILE* m_file;
};
/*!
Input adapter for a (caching) istream. Ignores a UFT Byte Order Mark at
beginning of input. Does not support changing the underlying std::streambuf
in mid-input. Maintains underlying std::istream and std::streambuf to support
subsequent use of standard std::istream operations to process any input
characters following those used in parsing the JSON input. Clears the
std::istream flags; any input errors (e.g., EOF) will be detected by the first
subsequent call for input from the std::istream.
*/
class input_stream_adapter : public input_adapter_protocol
{
public:
~input_stream_adapter() override
{
// clear stream flags; we use underlying streambuf I/O, do not
// maintain ifstream flags, except eof
is.clear(is.rdstate() & std::ios::eofbit);
}
explicit input_stream_adapter(std::istream& i)
: is(i), sb(*i.rdbuf())
{}
// delete because of pointer members
input_stream_adapter(const input_stream_adapter&) = delete;
input_stream_adapter& operator=(input_stream_adapter&) = delete;
input_stream_adapter(input_stream_adapter&&) = delete;
input_stream_adapter& operator=(input_stream_adapter&&) = delete;
// std::istream/std::streambuf use std::char_traits::to_int_type, to
// ensure that std::char_traits::eof() and the character 0xFF do not
// end up as the same value, eg. 0xFFFFFFFF.
std::char_traits::int_type get_character() override
{
auto res = sb.sbumpc();
// set eof manually, as we don’t use the istream interface.
if (res == EOF)
{
is.clear(is.rdstate() | std::ios::eofbit);
}
return res;
}
private:
/// the associated input stream
std::istream& is;
std::streambuf& sb;
};
/// input adapter for buffer input
class input_buffer_adapter : public input_adapter_protocol
{
public:
input_buffer_adapter(const char* b, const std::size_t l) noexcept
: cursor(b), limit(b + l)
{}
// delete because of pointer members
input_buffer_adapter(const input_buffer_adapter&) = delete;
input_buffer_adapter& operator=(input_buffer_adapter&) = delete;
input_buffer_adapter(input_buffer_adapter&&) = delete;
input_buffer_adapter& operator=(input_buffer_adapter&&) = delete;
~input_buffer_adapter() override = default;
std::char_traits::int_type get_character() noexcept override
{
if (JSON_LIKELY(cursor < limit))
{
return std::char_traits::to_int_type(*(cursor++));
}
return std::char_traits::eof();
}
private:
/// pointer to the current character
const char* cursor;
/// pointer past the last character
const char* const limit;
};
template
struct wide_string_input_helper
{
// UTF-32
static void fill_buffer(const WideStringType& str, size_t& current_wchar, std::array::int_type, 4>& utf8_bytes, size_t& utf8_bytes_index, size_t& utf8_bytes_filled)
{
utf8_bytes_index = 0;
if (current_wchar == str.size())
{
utf8_bytes[0] = std::char_traits::eof();
utf8_bytes_filled = 1;
}
else
{
// get the current character
const auto wc = static_cast(str[current_wchar++]);
// UTF-32 to UTF-8 encoding
if (wc < 0x80)
{
utf8_bytes[0] = wc;
utf8_bytes_filled = 1;
}
else if (wc <= 0x7FF)
{
utf8_bytes[0] = 0xC0 | ((wc >> 6) & 0x1F);
utf8_bytes[1] = 0x80 | (wc & 0x3F);
utf8_bytes_filled = 2;
}
else if (wc <= 0xFFFF)
{
utf8_bytes[0] = 0xE0 | ((wc >> 12) & 0x0F);
utf8_bytes[1] = 0x80 | ((wc >> 6) & 0x3F);
utf8_bytes[2] = 0x80 | (wc & 0x3F);
utf8_bytes_filled = 3;
}
else if (wc <= 0x10FFFF)
{
utf8_bytes[0] = 0xF0 | ((wc >> 18) & 0x07);
utf8_bytes[1] = 0x80 | ((wc >> 12) & 0x3F);
utf8_bytes[2] = 0x80 | ((wc >> 6) & 0x3F);
utf8_bytes[3] = 0x80 | (wc & 0x3F);
utf8_bytes_filled = 4;
}
else
{
// unknown character
utf8_bytes[0] = wc;
utf8_bytes_filled = 1;
}
}
}
};
template
struct wide_string_input_helper
{
// UTF-16
static void fill_buffer(const WideStringType& str, size_t& current_wchar, std::array::int_type, 4>& utf8_bytes, size_t& utf8_bytes_index, size_t& utf8_bytes_filled)
{
utf8_bytes_index = 0;
if (current_wchar == str.size())
{
utf8_bytes[0] = std::char_traits::eof();
utf8_bytes_filled = 1;
}
else
{
// get the current character
const auto wc = static_cast(str[current_wchar++]);
// UTF-16 to UTF-8 encoding
if (wc < 0x80)
{
utf8_bytes[0] = wc;
utf8_bytes_filled = 1;
}
else if (wc <= 0x7FF)
{
utf8_bytes[0] = 0xC0 | ((wc >> 6));
utf8_bytes[1] = 0x80 | (wc & 0x3F);
utf8_bytes_filled = 2;
}
else if (0xD800 > wc or wc >= 0xE000)
{
utf8_bytes[0] = 0xE0 | ((wc >> 12));
utf8_bytes[1] = 0x80 | ((wc >> 6) & 0x3F);
utf8_bytes[2] = 0x80 | (wc & 0x3F);
utf8_bytes_filled = 3;
}
else
{
if (current_wchar < str.size())
{
const auto wc2 = static_cast(str[current_wchar++]);
const int charcode = 0x10000 + (((wc & 0x3FF) << 10) | (wc2 & 0x3FF));
utf8_bytes[0] = 0xf0 | (charcode >> 18);
utf8_bytes[1] = 0x80 | ((charcode >> 12) & 0x3F);
utf8_bytes[2] = 0x80 | ((charcode >> 6) & 0x3F);
utf8_bytes[3] = 0x80 | (charcode & 0x3F);
utf8_bytes_filled = 4;
}
else
{
// unknown character
++current_wchar;
utf8_bytes[0] = wc;
utf8_bytes_filled = 1;
}
}
}
}
};
template
class wide_string_input_adapter : public input_adapter_protocol
{
public:
explicit wide_string_input_adapter(const WideStringType& w) noexcept
: str(w)
{}
std::char_traits::int_type get_character() noexcept override
{
// check if buffer needs to be filled
if (utf8_bytes_index == utf8_bytes_filled)
{
fill_buffer();
assert(utf8_bytes_filled > 0);
assert(utf8_bytes_index == 0);
}
// use buffer
assert(utf8_bytes_filled > 0);
assert(utf8_bytes_index < utf8_bytes_filled);
return utf8_bytes[utf8_bytes_index++];
}
private:
template
void fill_buffer()
{
wide_string_input_helper::fill_buffer(str, current_wchar, utf8_bytes, utf8_bytes_index, utf8_bytes_filled);
}
/// the wstring to process
const WideStringType& str;
/// index of the current wchar in str
std::size_t current_wchar = 0;
/// a buffer for UTF-8 bytes
std::array::int_type, 4> utf8_bytes = {{0, 0, 0, 0}};
/// index to the utf8_codes array for the next valid byte
std::size_t utf8_bytes_index = 0;
/// number of valid bytes in the utf8_codes array
std::size_t utf8_bytes_filled = 0;
};
class input_adapter
{
public:
// native support
input_adapter(std::FILE* file)
: ia(std::make_shared(file)) {}
/// input adapter for input stream
input_adapter(std::istream& i)
: ia(std::make_shared(i)) {}
/// input adapter for input stream
input_adapter(std::istream&& i)
: ia(std::make_shared(i)) {}
input_adapter(const std::wstring& ws)
: ia(std::make_shared>(ws)) {}
input_adapter(const std::u16string& ws)
: ia(std::make_shared>(ws)) {}
input_adapter(const std::u32string& ws)
: ia(std::make_shared>(ws)) {}
/// input adapter for buffer
template::value and
std::is_integral::type>::value and
sizeof(typename std::remove_pointer::type) == 1,
int>::type = 0>
input_adapter(CharT b, std::size_t l)
: ia(std::make_shared(reinterpret_cast(b), l)) {}
// derived support
/// input adapter for string literal
template::value and
std::is_integral::type>::value and
sizeof(typename std::remove_pointer::type) == 1,
int>::type = 0>
input_adapter(CharT b)
: input_adapter(reinterpret_cast(b),
std::strlen(reinterpret_cast(b))) {}
/// input adapter for iterator range with contiguous storage
template::iterator_category, std::random_access_iterator_tag>::value,
int>::type = 0>
input_adapter(IteratorType first, IteratorType last)
{
#ifndef NDEBUG
// assertion to check that the iterator range is indeed contiguous,
// see http://stackoverflow.com/a/35008842/266378 for more discussion
const auto is_contiguous = std::accumulate(
first, last, std::pair(true, 0),
[&first](std::pair res, decltype(*first) val)
{
res.first &= (val == *(std::next(std::addressof(*first), res.second++)));
return res;
}).first;
assert(is_contiguous);
#endif
// assertion to check that each element is 1 byte long
static_assert(
sizeof(typename iterator_traits::value_type) == 1,
“each element in the iterator range must have the size of 1 byte”);
const auto len = static_cast(std::distance(first, last));
if (JSON_LIKELY(len > 0))
{
// there is at least one element: use the address of first
ia = std::make_shared(reinterpret_cast(&(*first)), len);
}
else
{
// the address of first cannot be used: use nullptr
ia = std::make_shared(nullptr, len);
}
}
/// input adapter for array
template
input_adapter(T (&array)[N])
: input_adapter(std::begin(array), std::end(array)) {}
/// input adapter for contiguous container
template::value and
std::is_base_of()))>::iterator_category>::value,
int>::type = 0>
input_adapter(const ContiguousContainer& c)
: input_adapter(std::begin(c), std::end(c)) {}
operator input_adapter_t()
{
return ia;
}
private:
/// the actual adapter
input_adapter_t ia = nullptr;
};
} // namespace detail
} // namespace nlohmann
// #include
#include // localeconv
#include // size_t
#include // strtof, strtod, strtold, strtoll, strtoull
#include // snprintf
#include // initializer_list
#include // char_traits, string
#include // vector
// #include
// #include
// #include
namespace nlohmann
{
namespace detail
{
///////////
// lexer //
///////////
/*!
@brief lexical analysis
This class organizes the lexical analysis during JSON deserialization.
*/
template
class lexer
{
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using number_float_t = typename BasicJsonType::number_float_t;
using string_t = typename BasicJsonType::string_t;
public:
/// token types for the parser
enum class token_type
{
uninitialized, ///< indicating the scanner is uninitialized
literal_true, ///< the `true` literal
literal_false, ///< the `false` literal
literal_null, ///< the `null` literal
value_string, ///< a string -- use get_string() for actual value
value_unsigned, ///< an unsigned integer -- use get_number_unsigned() for actual value
value_integer, ///< a signed integer -- use get_number_integer() for actual value
value_float, ///< an floating point number -- use get_number_float() for actual value
begin_array, ///< the character for array begin `[`
begin_object, ///< the character for object begin `{`
end_array, ///< the character for array end `]`
end_object, ///< the character for object end `}`
name_separator, ///< the name separator `:`
value_separator, ///< the value separator `,`
parse_error, ///< indicating a parse error
end_of_input, ///< indicating the end of the input buffer
literal_or_value ///< a literal or the begin of a value (only for diagnostics)
};
/// return name of values of type token_type (only used for errors)
static const char* token_type_name(const token_type t) noexcept
{
switch (t)
{
case token_type::uninitialized:
return "“;
case token_type::literal_true:
return “true literal”;
case token_type::literal_false:
return “false literal”;
case token_type::literal_null:
return “null literal”;
case token_type::value_string:
return “string literal”;
case lexer::token_type::value_unsigned:
case lexer::token_type::value_integer:
case lexer::token_type::value_float:
return “number literal”;
case token_type::begin_array:
return “‘[‘”;
case token_type::begin_object:
return “‘{‘”;
case token_type::end_array:
return “‘]'”;
case token_type::end_object:
return “‘}'”;
case token_type::name_separator:
return “‘:'”;
case token_type::value_separator:
return “‘,'”;
case token_type::parse_error:
return ““;
case token_type::end_of_input:
return “end of input”;
case token_type::literal_or_value:
return “‘[‘, ‘{‘, or a literal”;
// LCOV_EXCL_START
default: // catch non-enum values
return “unknown token”;
// LCOV_EXCL_STOP
}
}
explicit lexer(detail::input_adapter_t&& adapter)
: ia(std::move(adapter)), decimal_point_char(get_decimal_point()) {}
// delete because of pointer members
lexer(const lexer&) = delete;
lexer(lexer&&) = delete;
lexer& operator=(lexer&) = delete;
lexer& operator=(lexer&&) = delete;
~lexer() = default;
private:
/////////////////////
// locales
/////////////////////
/// return the locale-dependent decimal point
static char get_decimal_point() noexcept
{
const auto loc = localeconv();
assert(loc != nullptr);
return (loc->decimal_point == nullptr) ? ‘.’ : *(loc->decimal_point);
}
/////////////////////
// scan functions
/////////////////////
/*!
@brief get codepoint from 4 hex characters following `\u`
For input “\u c1 c2 c3 c4” the codepoint is:
(c1 * 0x1000) + (c2 * 0x0100) + (c3 * 0x0010) + c4
= (c1 << 12) + (c2 << 8) + (c3 << 4) + (c4 << 0)
Furthermore, the possible characters '0'..'9', 'A'..'F', and 'a'..'f'
must be converted to the integers 0x0..0x9, 0xA..0xF, 0xA..0xF, resp. The
conversion is done by subtracting the offset (0x30, 0x37, and 0x57)
between the ASCII value of the character and the desired integer value.
@return codepoint (0x0000..0xFFFF) or -1 in case of an error (e.g. EOF or
non-hex character)
*/
int get_codepoint()
{
// this function only makes sense after reading `\u`
assert(current == 'u');
int codepoint = 0;
const auto factors = { 12, 8, 4, 0 };
for (const auto factor : factors)
{
get();
if (current >= ‘0’ and current <= '9')
{
codepoint += ((current - 0x30) << factor);
}
else if (current >= ‘A’ and current <= 'F')
{
codepoint += ((current - 0x37) << factor);
}
else if (current >= ‘a’ and current <= 'f')
{
codepoint += ((current - 0x57) << factor);
}
else
{
return -1;
}
}
assert(0x0000 <= codepoint and codepoint <= 0xFFFF);
return codepoint;
}
/*!
@brief check if the next byte(s) are inside a given range
Adds the current byte and, for each passed range, reads a new byte and
checks if it is inside the range. If a violation was detected, set up an
error message and return false. Otherwise, return true.
@param[in] ranges list of integers; interpreted as list of pairs of
inclusive lower and upper bound, respectively
@pre The passed list @a ranges must have 2, 4, or 6 elements; that is,
1, 2, or 3 pairs. This precondition is enforced by an assertion.
@return true if and only if no range violation was detected
*/
bool next_byte_in_range(std::initializer_list ranges)
{
assert(ranges.size() == 2 or ranges.size() == 4 or ranges.size() == 6);
add(current);
for (auto range = ranges.begin(); range != ranges.end(); ++range)
{
get();
if (JSON_LIKELY(*range <= current and current <= *(++range)))
{
add(current);
}
else
{
error_message = "invalid string: ill-formed UTF-8 byte";
return false;
}
}
return true;
}
/*!
@brief scan a string literal
This function scans a string according to Sect. 7 of RFC 7159. While
scanning, bytes are escaped and copied into buffer token_buffer. Then the
function returns successfully, token_buffer is *not* null-terminated (as it
may contain \0 bytes), and token_buffer.size() is the number of bytes in the
string.
@return token_type::value_string if string could be successfully scanned,
token_type::parse_error otherwise
@note In case of errors, variable error_message contains a textual
description.
*/
token_type scan_string()
{
// reset token_buffer (ignore opening quote)
reset();
// we entered the function by reading an open quote
assert(current == '\"');
while (true)
{
// get next character
switch (get())
{
// end of file while parsing string
case std::char_traits::eof():
{
error_message = “invalid string: missing closing quote”;
return token_type::parse_error;
}
// closing quote
case ‘\”‘:
{
return token_type::value_string;
}
// escapes
case ‘\\’:
{
switch (get())
{
// quotation mark
case ‘\”‘:
add(‘\”‘);
break;
// reverse solidus
case ‘\\’:
add(‘\\’);
break;
// solidus
case ‘/’:
add(‘/’);
break;
// backspace
case ‘b’:
add(‘\b’);
break;
// form feed
case ‘f’:
add(‘\f’);
break;
// line feed
case ‘n’:
add(‘\n’);
break;
// carriage return
case ‘r’:
add(‘\r’);
break;
// tab
case ‘t’:
add(‘\t’);
break;
// unicode escapes
case ‘u’:
{
const int codepoint1 = get_codepoint();
int codepoint = codepoint1; // start with codepoint1
if (JSON_UNLIKELY(codepoint1 == -1))
{
error_message = “invalid string: ‘\\u’ must be followed by 4 hex digits”;
return token_type::parse_error;
}
// check if code point is a high surrogate
if (0xD800 <= codepoint1 and codepoint1 <= 0xDBFF)
{
// expect next \uxxxx entry
if (JSON_LIKELY(get() == '\\' and get() == 'u'))
{
const int codepoint2 = get_codepoint();
if (JSON_UNLIKELY(codepoint2 == -1))
{
error_message = "invalid string: '\\u' must be followed by 4 hex digits";
return token_type::parse_error;
}
// check if codepoint2 is a low surrogate
if (JSON_LIKELY(0xDC00 <= codepoint2 and codepoint2 <= 0xDFFF))
{
// overwrite codepoint
codepoint =
// high surrogate occupies the most significant 22 bits
(codepoint1 << 10)
// low surrogate occupies the least significant 15 bits
+ codepoint2
// there is still the 0xD800, 0xDC00 and 0x10000 noise
// in the result so we have to subtract with:
// (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00
- 0x35FDC00;
}
else
{
error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF";
return token_type::parse_error;
}
}
else
{
error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF";
return token_type::parse_error;
}
}
else
{
if (JSON_UNLIKELY(0xDC00 <= codepoint1 and codepoint1 <= 0xDFFF))
{
error_message = "invalid string: surrogate U+DC00..U+DFFF must follow U+D800..U+DBFF";
return token_type::parse_error;
}
}
// result of the above calculation yields a proper codepoint
assert(0x00 <= codepoint and codepoint <= 0x10FFFF);
// translate codepoint into bytes
if (codepoint < 0x80)
{
// 1-byte characters: 0xxxxxxx (ASCII)
add(codepoint);
}
else if (codepoint <= 0x7FF)
{
// 2-byte characters: 110xxxxx 10xxxxxx
add(0xC0 | (codepoint >> 6));
add(0x80 | (codepoint & 0x3F));
}
else if (codepoint <= 0xFFFF)
{
// 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx
add(0xE0 | (codepoint >> 12));
add(0x80 | ((codepoint >> 6) & 0x3F));
add(0x80 | (codepoint & 0x3F));
}
else
{
// 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
add(0xF0 | (codepoint >> 18));
add(0x80 | ((codepoint >> 12) & 0x3F));
add(0x80 | ((codepoint >> 6) & 0x3F));
add(0x80 | (codepoint & 0x3F));
}
break;
}
// other characters after escape
default:
error_message = “invalid string: forbidden character after backslash”;
return token_type::parse_error;
}
break;
}
// invalid control characters
case 0x00:
{
error_message = “invalid string: control character U+0000 (NUL) must be escaped to \\u0000”;
return token_type::parse_error;
}
case 0x01:
{
error_message = “invalid string: control character U+0001 (SOH) must be escaped to \\u0001”;
return token_type::parse_error;
}
case 0x02:
{
error_message = “invalid string: control character U+0002 (STX) must be escaped to \\u0002”;
return token_type::parse_error;
}
case 0x03:
{
error_message = “invalid string: control character U+0003 (ETX) must be escaped to \\u0003”;
return token_type::parse_error;
}
case 0x04:
{
error_message = “invalid string: control character U+0004 (EOT) must be escaped to \\u0004”;
return token_type::parse_error;
}
case 0x05:
{
error_message = “invalid string: control character U+0005 (ENQ) must be escaped to \\u0005”;
return token_type::parse_error;
}
case 0x06:
{
error_message = “invalid string: control character U+0006 (ACK) must be escaped to \\u0006”;
return token_type::parse_error;
}
case 0x07:
{
error_message = “invalid string: control character U+0007 (BEL) must be escaped to \\u0007”;
return token_type::parse_error;
}
case 0x08:
{
error_message = “invalid string: control character U+0008 (BS) must be escaped to \\u0008 or \\b”;
return token_type::parse_error;
}
case 0x09:
{
error_message = “invalid string: control character U+0009 (HT) must be escaped to \\u0009 or \\t”;
return token_type::parse_error;
}
case 0x0A:
{
error_message = “invalid string: control character U+000A (LF) must be escaped to \\u000A or \\n”;
return token_type::parse_error;
}
case 0x0B:
{
error_message = “invalid string: control character U+000B (VT) must be escaped to \\u000B”;
return token_type::parse_error;
}
case 0x0C:
{
error_message = “invalid string: control character U+000C (FF) must be escaped to \\u000C or \\f”;
return token_type::parse_error;
}
case 0x0D:
{
error_message = “invalid string: control character U+000D (CR) must be escaped to \\u000D or \\r”;
return token_type::parse_error;
}
case 0x0E:
{
error_message = “invalid string: control character U+000E (SO) must be escaped to \\u000E”;
return token_type::parse_error;
}
case 0x0F:
{
error_message = “invalid string: control character U+000F (SI) must be escaped to \\u000F”;
return token_type::parse_error;
}
case 0x10:
{
error_message = “invalid string: control character U+0010 (DLE) must be escaped to \\u0010”;
return token_type::parse_error;
}
case 0x11:
{
error_message = “invalid string: control character U+0011 (DC1) must be escaped to \\u0011”;
return token_type::parse_error;
}
case 0x12:
{
error_message = “invalid string: control character U+0012 (DC2) must be escaped to \\u0012”;
return token_type::parse_error;
}
case 0x13:
{
error_message = “invalid string: control character U+0013 (DC3) must be escaped to \\u0013”;
return token_type::parse_error;
}
case 0x14:
{
error_message = “invalid string: control character U+0014 (DC4) must be escaped to \\u0014”;
return token_type::parse_error;
}
case 0x15:
{
error_message = “invalid string: control character U+0015 (NAK) must be escaped to \\u0015”;
return token_type::parse_error;
}
case 0x16:
{
error_message = “invalid string: control character U+0016 (SYN) must be escaped to \\u0016”;
return token_type::parse_error;
}
case 0x17:
{
error_message = “invalid string: control character U+0017 (ETB) must be escaped to \\u0017”;
return token_type::parse_error;
}
case 0x18:
{
error_message = “invalid string: control character U+0018 (CAN) must be escaped to \\u0018”;
return token_type::parse_error;
}
case 0x19:
{
error_message = “invalid string: control character U+0019 (EM) must be escaped to \\u0019”;
return token_type::parse_error;
}
case 0x1A:
{
error_message = “invalid string: control character U+001A (SUB) must be escaped to \\u001A”;
return token_type::parse_error;
}
case 0x1B:
{
error_message = “invalid string: control character U+001B (ESC) must be escaped to \\u001B”;
return token_type::parse_error;
}
case 0x1C:
{
error_message = “invalid string: control character U+001C (FS) must be escaped to \\u001C”;
return token_type::parse_error;
}
case 0x1D:
{
error_message = “invalid string: control character U+001D (GS) must be escaped to \\u001D”;
return token_type::parse_error;
}
case 0x1E:
{
error_message = “invalid string: control character U+001E (RS) must be escaped to \\u001E”;
return token_type::parse_error;
}
case 0x1F:
{
error_message = “invalid string: control character U+001F (US) must be escaped to \\u001F”;
return token_type::parse_error;
}
// U+0020..U+007F (except U+0022 (quote) and U+005C (backspace))
case 0x20:
case 0x21:
case 0x23:
case 0x24:
case 0x25:
case 0x26:
case 0x27:
case 0x28:
case 0x29:
case 0x2A:
case 0x2B:
case 0x2C:
case 0x2D:
case 0x2E:
case 0x2F:
case 0x30:
case 0x31:
case 0x32:
case 0x33:
case 0x34:
case 0x35:
case 0x36:
case 0x37:
case 0x38:
case 0x39:
case 0x3A:
case 0x3B:
case 0x3C:
case 0x3D:
case 0x3E:
case 0x3F:
case 0x40:
case 0x41:
case 0x42:
case 0x43:
case 0x44:
case 0x45:
case 0x46:
case 0x47:
case 0x48:
case 0x49:
case 0x4A:
case 0x4B:
case 0x4C:
case 0x4D:
case 0x4E:
case 0x4F:
case 0x50:
case 0x51:
case 0x52:
case 0x53:
case 0x54:
case 0x55:
case 0x56:
case 0x57:
case 0x58:
case 0x59:
case 0x5A:
case 0x5B:
case 0x5D:
case 0x5E:
case 0x5F:
case 0x60:
case 0x61:
case 0x62:
case 0x63:
case 0x64:
case 0x65:
case 0x66:
case 0x67:
case 0x68:
case 0x69:
case 0x6A:
case 0x6B:
case 0x6C:
case 0x6D:
case 0x6E:
case 0x6F:
case 0x70:
case 0x71:
case 0x72:
case 0x73:
case 0x74:
case 0x75:
case 0x76:
case 0x77:
case 0x78:
case 0x79:
case 0x7A:
case 0x7B:
case 0x7C:
case 0x7D:
case 0x7E:
case 0x7F:
{
add(current);
break;
}
// U+0080..U+07FF: bytes C2..DF 80..BF
case 0xC2:
case 0xC3:
case 0xC4:
case 0xC5:
case 0xC6:
case 0xC7:
case 0xC8:
case 0xC9:
case 0xCA:
case 0xCB:
case 0xCC:
case 0xCD:
case 0xCE:
case 0xCF:
case 0xD0:
case 0xD1:
case 0xD2:
case 0xD3:
case 0xD4:
case 0xD5:
case 0xD6:
case 0xD7:
case 0xD8:
case 0xD9:
case 0xDA:
case 0xDB:
case 0xDC:
case 0xDD:
case 0xDE:
case 0xDF:
{
if (JSON_UNLIKELY(not next_byte_in_range({0x80, 0xBF})))
{
return token_type::parse_error;
}
break;
}
// U+0800..U+0FFF: bytes E0 A0..BF 80..BF
case 0xE0:
{
if (JSON_UNLIKELY(not (next_byte_in_range({0xA0, 0xBF, 0x80, 0xBF}))))
{
return token_type::parse_error;
}
break;
}
// U+1000..U+CFFF: bytes E1..EC 80..BF 80..BF
// U+E000..U+FFFF: bytes EE..EF 80..BF 80..BF
case 0xE1:
case 0xE2:
case 0xE3:
case 0xE4:
case 0xE5:
case 0xE6:
case 0xE7:
case 0xE8:
case 0xE9:
case 0xEA:
case 0xEB:
case 0xEC:
case 0xEE:
case 0xEF:
{
if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF}))))
{
return token_type::parse_error;
}
break;
}
// U+D000..U+D7FF: bytes ED 80..9F 80..BF
case 0xED:
{
if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0x9F, 0x80, 0xBF}))))
{
return token_type::parse_error;
}
break;
}
// U+10000..U+3FFFF F0 90..BF 80..BF 80..BF
case 0xF0:
{
if (JSON_UNLIKELY(not (next_byte_in_range({0x90, 0xBF, 0x80, 0xBF, 0x80, 0xBF}))))
{
return token_type::parse_error;
}
break;
}
// U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF
case 0xF1:
case 0xF2:
case 0xF3:
{
if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF, 0x80, 0xBF}))))
{
return token_type::parse_error;
}
break;
}
// U+100000..U+10FFFF F4 80..8F 80..BF 80..BF
case 0xF4:
{
if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0x8F, 0x80, 0xBF, 0x80, 0xBF}))))
{
return token_type::parse_error;
}
break;
}
// remaining bytes (80..C1 and F5..FF) are ill-formed
default:
{
error_message = “invalid string: ill-formed UTF-8 byte”;
return token_type::parse_error;
}
}
}
}
static void strtof(float& f, const char* str, char** endptr) noexcept
{
f = std::strtof(str, endptr);
}
static void strtof(double& f, const char* str, char** endptr) noexcept
{
f = std::strtod(str, endptr);
}
static void strtof(long double& f, const char* str, char** endptr) noexcept
{
f = std::strtold(str, endptr);
}
/*!
@brief scan a number literal
This function scans a string according to Sect. 6 of RFC 7159.
The function is realized with a deterministic finite state machine derived
from the grammar described in RFC 7159. Starting in state “init”, the
input is read and used to determined the next state. Only state “done”
accepts the number. State “error” is a trap state to model errors. In the
table below, “anything” means any character but the ones listed before.
state | 0 | 1-9 | e E | + | – | . | anything
———|———-|———-|———-|———|———|———-|———–
init | zero | any1 | [error] | [error] | minus | [error] | [error]
minus | zero | any1 | [error] | [error] | [error] | [error] | [error]
zero | done | done | exponent | done | done | decimal1 | done
any1 | any1 | any1 | exponent | done | done | decimal1 | done
decimal1 | decimal2 | [error] | [error] | [error] | [error] | [error] | [error]
decimal2 | decimal2 | decimal2 | exponent | done | done | done | done
exponent | any2 | any2 | [error] | sign | sign | [error] | [error]
sign | any2 | any2 | [error] | [error] | [error] | [error] | [error]
any2 | any2 | any2 | done | done | done | done | done
The state machine is realized with one label per state (prefixed with
“scan_number_”) and `goto` statements between them. The state machine
contains cycles, but any cycle can be left when EOF is read. Therefore,
the function is guaranteed to terminate.
During scanning, the read bytes are stored in token_buffer. This string is
then converted to a signed integer, an unsigned integer, or a
floating-point number.
@return token_type::value_unsigned, token_type::value_integer, or
token_type::value_float if number could be successfully scanned,
token_type::parse_error otherwise
@note The scanner is independent of the current locale. Internally, the
locale’s decimal point is used instead of `.` to work with the
locale-dependent converters.
*/
token_type scan_number() // lgtm [cpp/use-of-goto]
{
// reset token_buffer to store the number’s bytes
reset();
// the type of the parsed number; initially set to unsigned; will be
// changed if minus sign, decimal point or exponent is read
token_type number_type = token_type::value_unsigned;
// state (init): we just found out we need to scan a number
switch (current)
{
case ‘-‘:
{
add(current);
goto scan_number_minus;
}
case ‘0’:
{
add(current);
goto scan_number_zero;
}
case ‘1’:
case ‘2’:
case ‘3’:
case ‘4’:
case ‘5’:
case ‘6’:
case ‘7’:
case ‘8’:
case ‘9’:
{
add(current);
goto scan_number_any1;
}
// LCOV_EXCL_START
default:
{
// all other characters are rejected outside scan_number()
assert(false);
}
// LCOV_EXCL_STOP
}
scan_number_minus:
// state: we just parsed a leading minus sign
number_type = token_type::value_integer;
switch (get())
{
case ‘0’:
{
add(current);
goto scan_number_zero;
}
case ‘1’:
case ‘2’:
case ‘3’:
case ‘4’:
case ‘5’:
case ‘6’:
case ‘7’:
case ‘8’:
case ‘9’:
{
add(current);
goto scan_number_any1;
}
default:
{
error_message = “invalid number; expected digit after ‘-‘”;
return token_type::parse_error;
}
}
scan_number_zero:
// state: we just parse a zero (maybe with a leading minus sign)
switch (get())
{
case ‘.’:
{
add(decimal_point_char);
goto scan_number_decimal1;
}
case ‘e’:
case ‘E’:
{
add(current);
goto scan_number_exponent;
}
default:
goto scan_number_done;
}
scan_number_any1:
// state: we just parsed a number 0-9 (maybe with a leading minus sign)
switch (get())
{
case ‘0’:
case ‘1’:
case ‘2’:
case ‘3’:
case ‘4’:
case ‘5’:
case ‘6’:
case ‘7’:
case ‘8’:
case ‘9’:
{
add(current);
goto scan_number_any1;
}
case ‘.’:
{
add(decimal_point_char);
goto scan_number_decimal1;
}
case ‘e’:
case ‘E’:
{
add(current);
goto scan_number_exponent;
}
default:
goto scan_number_done;
}
scan_number_decimal1:
// state: we just parsed a decimal point
number_type = token_type::value_float;
switch (get())
{
case ‘0’:
case ‘1’:
case ‘2’:
case ‘3’:
case ‘4’:
case ‘5’:
case ‘6’:
case ‘7’:
case ‘8’:
case ‘9’:
{
add(current);
goto scan_number_decimal2;
}
default:
{
error_message = “invalid number; expected digit after ‘.'”;
return token_type::parse_error;
}
}
scan_number_decimal2:
// we just parsed at least one number after a decimal point
switch (get())
{
case ‘0’:
case ‘1’:
case ‘2’:
case ‘3’:
case ‘4’:
case ‘5’:
case ‘6’:
case ‘7’:
case ‘8’:
case ‘9’:
{
add(current);
goto scan_number_decimal2;
}
case ‘e’:
case ‘E’:
{
add(current);
goto scan_number_exponent;
}
default:
goto scan_number_done;
}
scan_number_exponent:
// we just parsed an exponent
number_type = token_type::value_float;
switch (get())
{
case ‘+’:
case ‘-‘:
{
add(current);
goto scan_number_sign;
}
case ‘0’:
case ‘1’:
case ‘2’:
case ‘3’:
case ‘4’:
case ‘5’:
case ‘6’:
case ‘7’:
case ‘8’:
case ‘9’:
{
add(current);
goto scan_number_any2;
}
default:
{
error_message =
“invalid number; expected ‘+’, ‘-‘, or digit after exponent”;
return token_type::parse_error;
}
}
scan_number_sign:
// we just parsed an exponent sign
switch (get())
{
case ‘0’:
case ‘1’:
case ‘2’:
case ‘3’:
case ‘4’:
case ‘5’:
case ‘6’:
case ‘7’:
case ‘8’:
case ‘9’:
{
add(current);
goto scan_number_any2;
}
default:
{
error_message = “invalid number; expected digit after exponent sign”;
return token_type::parse_error;
}
}
scan_number_any2:
// we just parsed a number after the exponent or exponent sign
switch (get())
{
case ‘0’:
case ‘1’:
case ‘2’:
case ‘3’:
case ‘4’:
case ‘5’:
case ‘6’:
case ‘7’:
case ‘8’:
case ‘9’:
{
add(current);
goto scan_number_any2;
}
default:
goto scan_number_done;
}
scan_number_done:
// unget the character after the number (we only read it to know that
// we are done scanning a number)
unget();
char* endptr = nullptr;
errno = 0;
// try to parse integers first and fall back to floats
if (number_type == token_type::value_unsigned)
{
const auto x = std::strtoull(token_buffer.data(), &endptr, 10);
// we checked the number format before
assert(endptr == token_buffer.data() + token_buffer.size());
if (errno == 0)
{
value_unsigned = static_cast(x);
if (value_unsigned == x)
{
return token_type::value_unsigned;
}
}
}
else if (number_type == token_type::value_integer)
{
const auto x = std::strtoll(token_buffer.data(), &endptr, 10);
// we checked the number format before
assert(endptr == token_buffer.data() + token_buffer.size());
if (errno == 0)
{
value_integer = static_cast(x);
if (value_integer == x)
{
return token_type::value_integer;
}
}
}
// this code is reached if we parse a floating-point number or if an
// integer conversion above failed
strtof(value_float, token_buffer.data(), &endptr);
// we checked the number format before
assert(endptr == token_buffer.data() + token_buffer.size());
return token_type::value_float;
}
/*!
@param[in] literal_text the literal text to expect
@param[in] length the length of the passed literal text
@param[in] return_type the token type to return on success
*/
token_type scan_literal(const char* literal_text, const std::size_t length,
token_type return_type)
{
assert(current == literal_text[0]);
for (std::size_t i = 1; i < length; ++i)
{
if (JSON_UNLIKELY(get() != literal_text[i]))
{
error_message = "invalid literal";
return token_type::parse_error;
}
}
return return_type;
}
/////////////////////
// input management
/////////////////////
/// reset token_buffer; current character is beginning of token
void reset() noexcept
{
token_buffer.clear();
token_string.clear();
token_string.push_back(std::char_traits::to_char_type(current));
}
/*
@brief get next character from the input
This function provides the interface to the used input adapter. It does
not throw in case the input reached EOF, but returns a
`std::char_traits::eof()` in that case. Stores the scanned characters
for use in error messages.
@return character read from the input
*/
std::char_traits::int_type get()
{
++position.chars_read_total;
++position.chars_read_current_line;
if (next_unget)
{
// just reset the next_unget variable and work with current
next_unget = false;
}
else
{
current = ia->get_character();
}
if (JSON_LIKELY(current != std::char_traits::eof()))
{
token_string.push_back(std::char_traits::to_char_type(current));
}
if (current == ‘\n’)
{
++position.lines_read;
position.chars_read_current_line = 0;
}
return current;
}
/*!
@brief unget current character (read it again on next get)
We implement unget by setting variable next_unget to true. The input is not
changed – we just simulate ungetting by modifying chars_read_total,
chars_read_current_line, and token_string. The next call to get() will
behave as if the unget character is read again.
*/
void unget()
{
next_unget = true;
–position.chars_read_total;
// in case we “unget” a newline, we have to also decrement the lines_read
if (position.chars_read_current_line == 0)
{
if (position.lines_read > 0)
{
–position.lines_read;
}
}
else
{
–position.chars_read_current_line;
}
if (JSON_LIKELY(current != std::char_traits::eof()))
{
assert(token_string.size() != 0);
token_string.pop_back();
}
}
/// add a character to token_buffer
void add(int c)
{
token_buffer.push_back(std::char_traits::to_char_type(c));
}
public:
/////////////////////
// value getters
/////////////////////
/// return integer value
constexpr number_integer_t get_number_integer() const noexcept
{
return value_integer;
}
/// return unsigned integer value
constexpr number_unsigned_t get_number_unsigned() const noexcept
{
return value_unsigned;
}
/// return floating-point value
constexpr number_float_t get_number_float() const noexcept
{
return value_float;
}
/// return current string value (implicitly resets the token; useful only once)
string_t& get_string()
{
return token_buffer;
}
/////////////////////
// diagnostics
/////////////////////
/// return position of last read token
constexpr position_t get_position() const noexcept
{
return position;
}
/// return the last read token (for errors only). Will never contain EOF
/// (an arbitrary value that is not a valid char value, often -1), because
/// 255 may legitimately occur. May contain NUL, which should be escaped.
std::string get_token_string() const
{
// escape control characters
std::string result;
for (const auto c : token_string)
{
if (‘\x00’ <= c and c <= '\x1F')
{
// escape control characters
char cs[9];
(std::snprintf)(cs, 9, "“, static_cast(c));
result += cs;
}
else
{
// add character as is
result.push_back(c);
}
}
return result;
}
/// return syntax error message
constexpr const char* get_error_message() const noexcept
{
return error_message;
}
/////////////////////
// actual scanner
/////////////////////
/*!
@brief skip the UTF-8 byte order mark
@return true iff there is no BOM or the correct BOM has been skipped
*/
bool skip_bom()
{
if (get() == 0xEF)
{
// check if we completely parse the BOM
return get() == 0xBB and get() == 0xBF;
}
// the first character is not the beginning of the BOM; unget it to
// process is later
unget();
return true;
}
token_type scan()
{
// initially, skip the BOM
if (position.chars_read_total == 0 and not skip_bom())
{
error_message = “invalid BOM; must be 0xEF 0xBB 0xBF if given”;
return token_type::parse_error;
}
// read next character and ignore whitespace
do
{
get();
}
while (current == ‘ ‘ or current == ‘\t’ or current == ‘\n’ or current == ‘\r’);
switch (current)
{
// structural characters
case ‘[‘:
return token_type::begin_array;
case ‘]’:
return token_type::end_array;
case ‘{‘:
return token_type::begin_object;
case ‘}’:
return token_type::end_object;
case ‘:’:
return token_type::name_separator;
case ‘,’:
return token_type::value_separator;
// literals
case ‘t’:
return scan_literal(“true”, 4, token_type::literal_true);
case ‘f’:
return scan_literal(“false”, 5, token_type::literal_false);
case ‘n’:
return scan_literal(“null”, 4, token_type::literal_null);
// string
case ‘\”‘:
return scan_string();
// number
case ‘-‘:
case ‘0’:
case ‘1’:
case ‘2’:
case ‘3’:
case ‘4’:
case ‘5’:
case ‘6’:
case ‘7’:
case ‘8’:
case ‘9’:
return scan_number();
// end of input (the null byte is needed when parsing from
// string literals)
case ‘\0’:
case std::char_traits::eof():
return token_type::end_of_input;
// error
default:
error_message = “invalid literal”;
return token_type::parse_error;
}
}
private:
/// input adapter
detail::input_adapter_t ia = nullptr;
/// the current character
std::char_traits::int_type current = std::char_traits::eof();
/// whether the next get() call should just return current
bool next_unget = false;
/// the start position of the current token
position_t position;
/// raw input token string (for error messages)
std::vector token_string {};
/// buffer for variable-length tokens (numbers, strings)
string_t token_buffer {};
/// a description of occurred lexer errors
const char* error_message = “”;
// number values
number_integer_t value_integer = 0;
number_unsigned_t value_unsigned = 0;
number_float_t value_float = 0;
/// the decimal point
const char decimal_point_char = ‘.’;
};
} // namespace detail
} // namespace nlohmann
// #include
#include // assert
#include // isfinite
#include // uint8_t
#include // function
#include // string
#include // move
// #include
// #include
// #include
#include // size_t
#include // declval
// #include
// #include
namespace nlohmann
{
namespace detail
{
template
using null_function_t = decltype(std::declval().null());
template
using boolean_function_t =
decltype(std::declval().boolean(std::declval()));
template
using number_integer_function_t =
decltype(std::declval().number_integer(std::declval()));
template
using number_unsigned_function_t =
decltype(std::declval().number_unsigned(std::declval()));
template
using number_float_function_t = decltype(std::declval().number_float(
std::declval(), std::declval()));
template
using string_function_t =
decltype(std::declval().string(std::declval()));
template
using start_object_function_t =
decltype(std::declval().start_object(std::declval()));
template
using key_function_t =
decltype(std::declval().key(std::declval()));
template
using end_object_function_t = decltype(std::declval().end_object());
template
using start_array_function_t =
decltype(std::declval().start_array(std::declval()));
template
using end_array_function_t = decltype(std::declval().end_array());
template
using parse_error_function_t = decltype(std::declval().parse_error(
std::declval(), std::declval(),
std::declval()));
template
struct is_sax
{
private:
static_assert(is_basic_json::value,
“BasicJsonType must be of type basic_json<...>“);
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using number_float_t = typename BasicJsonType::number_float_t;
using string_t = typename BasicJsonType::string_t;
using exception_t = typename BasicJsonType::exception;
public:
static constexpr bool value =
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value &&
is_detected_exact::value;
};
template
struct is_sax_static_asserts
{
private:
static_assert(is_basic_json::value,
“BasicJsonType must be of type basic_json<...>“);
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using number_float_t = typename BasicJsonType::number_float_t;
using string_t = typename BasicJsonType::string_t;
using exception_t = typename BasicJsonType::exception;
public:
static_assert(is_detected_exact::value,
“Missing/invalid function: bool null()”);
static_assert(is_detected_exact::value,
“Missing/invalid function: bool boolean(bool)”);
static_assert(is_detected_exact::value,
“Missing/invalid function: bool boolean(bool)”);
static_assert(
is_detected_exact::value,
“Missing/invalid function: bool number_integer(number_integer_t)”);
static_assert(
is_detected_exact::value,
“Missing/invalid function: bool number_unsigned(number_unsigned_t)”);
static_assert(is_detected_exact::value,
“Missing/invalid function: bool number_float(number_float_t, const string_t&)”);
static_assert(
is_detected_exact::value,
“Missing/invalid function: bool string(string_t&)”);
static_assert(is_detected_exact::value,
“Missing/invalid function: bool start_object(std::size_t)”);
static_assert(is_detected_exact::value,
“Missing/invalid function: bool key(string_t&)”);
static_assert(is_detected_exact::value,
“Missing/invalid function: bool end_object()”);
static_assert(is_detected_exact::value,
“Missing/invalid function: bool start_array(std::size_t)”);
static_assert(is_detected_exact::value,
“Missing/invalid function: bool end_array()”);
static_assert(
is_detected_exact::value,
“Missing/invalid function: bool parse_error(std::size_t, const ”
“std::string&, const exception&)”);
};
} // namespace detail
} // namespace nlohmann
// #include
// #include
#include
#include
#include
#include
// #include
// #include
namespace nlohmann
{
/*!
@brief SAX interface
This class describes the SAX interface used by @ref nlohmann::json::sax_parse.
Each function is called in different situations while the input is parsed. The
boolean return value informs the parser whether to continue processing the
input.
*/
template
struct json_sax
{
/// type for (signed) integers
using number_integer_t = typename BasicJsonType::number_integer_t;
/// type for unsigned integers
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
/// type for floating-point numbers
using number_float_t = typename BasicJsonType::number_float_t;
/// type for strings
using string_t = typename BasicJsonType::string_t;
/*!
@brief a null value was read
@return whether parsing should proceed
*/
virtual bool null() = 0;
/*!
@brief a boolean value was read
@param[in] val boolean value
@return whether parsing should proceed
*/
virtual bool boolean(bool val) = 0;
/*!
@brief an integer number was read
@param[in] val integer value
@return whether parsing should proceed
*/
virtual bool number_integer(number_integer_t val) = 0;
/*!
@brief an unsigned integer number was read
@param[in] val unsigned integer value
@return whether parsing should proceed
*/
virtual bool number_unsigned(number_unsigned_t val) = 0;
/*!
@brief an floating-point number was read
@param[in] val floating-point value
@param[in] s raw token value
@return whether parsing should proceed
*/
virtual bool number_float(number_float_t val, const string_t& s) = 0;
/*!
@brief a string was read
@param[in] val string value
@return whether parsing should proceed
@note It is safe to move the passed string.
*/
virtual bool string(string_t& val) = 0;
/*!
@brief the beginning of an object was read
@param[in] elements number of object elements or -1 if unknown
@return whether parsing should proceed
@note binary formats may report the number of elements
*/
virtual bool start_object(std::size_t elements) = 0;
/*!
@brief an object key was read
@param[in] val object key
@return whether parsing should proceed
@note It is safe to move the passed string.
*/
virtual bool key(string_t& val) = 0;
/*!
@brief the end of an object was read
@return whether parsing should proceed
*/
virtual bool end_object() = 0;
/*!
@brief the beginning of an array was read
@param[in] elements number of array elements or -1 if unknown
@return whether parsing should proceed
@note binary formats may report the number of elements
*/
virtual bool start_array(std::size_t elements) = 0;
/*!
@brief the end of an array was read
@return whether parsing should proceed
*/
virtual bool end_array() = 0;
/*!
@brief a parse error occurred
@param[in] position the position in the input where the error occurs
@param[in] last_token the last read token
@param[in] ex an exception object describing the error
@return whether parsing should proceed (must return false)
*/
virtual bool parse_error(std::size_t position,
const std::string& last_token,
const detail::exception& ex) = 0;
virtual ~json_sax() = default;
};
namespace detail
{
/*!
@brief SAX implementation to create a JSON value from SAX events
This class implements the @ref json_sax interface and processes the SAX events
to create a JSON value which makes it basically a DOM parser. The structure or
hierarchy of the JSON value is managed by the stack `ref_stack` which contains
a pointer to the respective array or object for each recursion depth.
After successful parsing, the value that is passed by reference to the
constructor contains the parsed value.
@tparam BasicJsonType the JSON type
*/
template
class json_sax_dom_parser
{
public:
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using number_float_t = typename BasicJsonType::number_float_t;
using string_t = typename BasicJsonType::string_t;
/*!
@param[in, out] r reference to a JSON value that is manipulated while
parsing
@param[in] allow_exceptions_ whether parse errors yield exceptions
*/
explicit json_sax_dom_parser(BasicJsonType& r, const bool allow_exceptions_ = true)
: root(r), allow_exceptions(allow_exceptions_)
{}
bool null()
{
handle_value(nullptr);
return true;
}
bool boolean(bool val)
{
handle_value(val);
return true;
}
bool number_integer(number_integer_t val)
{
handle_value(val);
return true;
}
bool number_unsigned(number_unsigned_t val)
{
handle_value(val);
return true;
}
bool number_float(number_float_t val, const string_t& /*unused*/)
{
handle_value(val);
return true;
}
bool string(string_t& val)
{
handle_value(val);
return true;
}
bool start_object(std::size_t len)
{
ref_stack.push_back(handle_value(BasicJsonType::value_t::object));
if (JSON_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size()))
{
JSON_THROW(out_of_range::create(408,
“excessive object size: ” + std::to_string(len)));
}
return true;
}
bool key(string_t& val)
{
// add null at given key and store the reference for later
object_element = &(ref_stack.back()->m_value.object->operator[](val));
return true;
}
bool end_object()
{
ref_stack.pop_back();
return true;
}
bool start_array(std::size_t len)
{
ref_stack.push_back(handle_value(BasicJsonType::value_t::array));
if (JSON_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size()))
{
JSON_THROW(out_of_range::create(408,
“excessive array size: ” + std::to_string(len)));
}
return true;
}
bool end_array()
{
ref_stack.pop_back();
return true;
}
bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/,
const detail::exception& ex)
{
errored = true;
if (allow_exceptions)
{
// determine the proper exception type from the id
switch ((ex.id / 100) % 100)
{
case 1:
JSON_THROW(*reinterpret_cast(&ex));
case 4:
JSON_THROW(*reinterpret_cast(&ex));
// LCOV_EXCL_START
case 2:
JSON_THROW(*reinterpret_cast(&ex));
case 3:
JSON_THROW(*reinterpret_cast(&ex));
case 5:
JSON_THROW(*reinterpret_cast(&ex));
default:
assert(false);
// LCOV_EXCL_STOP
}
}
return false;
}
constexpr bool is_errored() const
{
return errored;
}
private:
/*!
@invariant If the ref stack is empty, then the passed value will be the new
root.
@invariant If the ref stack contains a value, then it is an array or an
object to which we can add elements
*/
template
BasicJsonType* handle_value(Value&& v)
{
if (ref_stack.empty())
{
root = BasicJsonType(std::forward(v));
return &root;
}
assert(ref_stack.back()->is_array() or ref_stack.back()->is_object());
if (ref_stack.back()->is_array())
{
ref_stack.back()->m_value.array->emplace_back(std::forward(v));
return &(ref_stack.back()->m_value.array->back());
}
else
{
assert(object_element);
*object_element = BasicJsonType(std::forward(v));
return object_element;
}
}
/// the parsed JSON value
BasicJsonType& root;
/// stack to model hierarchy of values
std::vector ref_stack;
/// helper to hold the reference for the next object element
BasicJsonType* object_element = nullptr;
/// whether a syntax error occurred
bool errored = false;
/// whether to throw exceptions in case of errors
const bool allow_exceptions = true;
};
template
class json_sax_dom_callback_parser
{
public:
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using number_float_t = typename BasicJsonType::number_float_t;
using string_t = typename BasicJsonType::string_t;
using parser_callback_t = typename BasicJsonType::parser_callback_t;
using parse_event_t = typename BasicJsonType::parse_event_t;
json_sax_dom_callback_parser(BasicJsonType& r,
const parser_callback_t cb,
const bool allow_exceptions_ = true)
: root(r), callback(cb), allow_exceptions(allow_exceptions_)
{
keep_stack.push_back(true);
}
bool null()
{
handle_value(nullptr);
return true;
}
bool boolean(bool val)
{
handle_value(val);
return true;
}
bool number_integer(number_integer_t val)
{
handle_value(val);
return true;
}
bool number_unsigned(number_unsigned_t val)
{
handle_value(val);
return true;
}
bool number_float(number_float_t val, const string_t& /*unused*/)
{
handle_value(val);
return true;
}
bool string(string_t& val)
{
handle_value(val);
return true;
}
bool start_object(std::size_t len)
{
// check callback for object start
const bool keep = callback(static_cast(ref_stack.size()), parse_event_t::object_start, discarded);
keep_stack.push_back(keep);
auto val = handle_value(BasicJsonType::value_t::object, true);
ref_stack.push_back(val.second);
// check object limit
if (ref_stack.back())
{
if (JSON_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size()))
{
JSON_THROW(out_of_range::create(408,
“excessive object size: ” + std::to_string(len)));
}
}
return true;
}
bool key(string_t& val)
{
BasicJsonType k = BasicJsonType(val);
// check callback for key
const bool keep = callback(static_cast(ref_stack.size()), parse_event_t::key, k);
key_keep_stack.push_back(keep);
// add discarded value at given key and store the reference for later
if (keep and ref_stack.back())
{
object_element = &(ref_stack.back()->m_value.object->operator[](val) = discarded);
}
return true;
}
bool end_object()
{
if (ref_stack.back())
{
if (not callback(static_cast(ref_stack.size()) – 1, parse_event_t::object_end, *ref_stack.back()))
{
// discard object
*ref_stack.back() = discarded;
}
}
assert(not ref_stack.empty());
assert(not keep_stack.empty());
ref_stack.pop_back();
keep_stack.pop_back();
if (not ref_stack.empty() and ref_stack.back())
{
// remove discarded value
if (ref_stack.back()->is_object())
{
for (auto it = ref_stack.back()->begin(); it != ref_stack.back()->end(); ++it)
{
if (it->is_discarded())
{
ref_stack.back()->erase(it);
break;
}
}
}
}
return true;
}
bool start_array(std::size_t len)
{
const bool keep = callback(static_cast(ref_stack.size()), parse_event_t::array_start, discarded);
keep_stack.push_back(keep);
auto val = handle_value(BasicJsonType::value_t::array, true);
ref_stack.push_back(val.second);
// check array limit
if (ref_stack.back())
{
if (JSON_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size()))
{
JSON_THROW(out_of_range::create(408,
“excessive array size: ” + std::to_string(len)));
}
}
return true;
}
bool end_array()
{
bool keep = true;
if (ref_stack.back())
{
keep = callback(static_cast(ref_stack.size()) – 1, parse_event_t::array_end, *ref_stack.back());
if (not keep)
{
// discard array
*ref_stack.back() = discarded;
}
}
assert(not ref_stack.empty());
assert(not keep_stack.empty());
ref_stack.pop_back();
keep_stack.pop_back();
// remove discarded value
if (not keep and not ref_stack.empty())
{
if (ref_stack.back()->is_array())
{
ref_stack.back()->m_value.array->pop_back();
}
}
return true;
}
bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/,
const detail::exception& ex)
{
errored = true;
if (allow_exceptions)
{
// determine the proper exception type from the id
switch ((ex.id / 100) % 100)
{
case 1:
JSON_THROW(*reinterpret_cast(&ex));
case 4:
JSON_THROW(*reinterpret_cast(&ex));
// LCOV_EXCL_START
case 2:
JSON_THROW(*reinterpret_cast(&ex));
case 3:
JSON_THROW(*reinterpret_cast(&ex));
case 5:
JSON_THROW(*reinterpret_cast(&ex));
default:
assert(false);
// LCOV_EXCL_STOP
}
}
return false;
}
constexpr bool is_errored() const
{
return errored;
}
private:
/*!
@param[in] v value to add to the JSON value we build during parsing
@param[in] skip_callback whether we should skip calling the callback
function; this is required after start_array() and
start_object() SAX events, because otherwise we would call the
callback function with an empty array or object, respectively.
@invariant If the ref stack is empty, then the passed value will be the new
root.
@invariant If the ref stack contains a value, then it is an array or an
object to which we can add elements
@return pair of boolean (whether value should be kept) and pointer (to the
passed value in the ref_stack hierarchy; nullptr if not kept)
*/
template
std::pair handle_value(Value&& v, const bool skip_callback = false)
{
assert(not keep_stack.empty());
// do not handle this value if we know it would be added to a discarded
// container
if (not keep_stack.back())
{
return {false, nullptr};
}
// create value
auto value = BasicJsonType(std::forward(v));
// check callback
const bool keep = skip_callback or callback(static_cast(ref_stack.size()), parse_event_t::value, value);
// do not handle this value if we just learnt it shall be discarded
if (not keep)
{
return {false, nullptr};
}
if (ref_stack.empty())
{
root = std::move(value);
return {true, &root};
}
// skip this value if we already decided to skip the parent
// (https://github.com/nlohmann/json/issues/971#issuecomment-413678360)
if (not ref_stack.back())
{
return {false, nullptr};
}
// we now only expect arrays and objects
assert(ref_stack.back()->is_array() or ref_stack.back()->is_object());
if (ref_stack.back()->is_array())
{
ref_stack.back()->m_value.array->push_back(std::move(value));
return {true, &(ref_stack.back()->m_value.array->back())};
}
else
{
// check if we should store an element for the current key
assert(not key_keep_stack.empty());
const bool store_element = key_keep_stack.back();
key_keep_stack.pop_back();
if (not store_element)
{
return {false, nullptr};
}
assert(object_element);
*object_element = std::move(value);
return {true, object_element};
}
}
/// the parsed JSON value
BasicJsonType& root;
/// stack to model hierarchy of values
std::vector ref_stack;
/// stack to manage which values to keep
std::vector keep_stack;
/// stack to manage which object keys to keep
std::vector key_keep_stack;
/// helper to hold the reference for the next object element
BasicJsonType* object_element = nullptr;
/// whether a syntax error occurred
bool errored = false;
/// callback function
const parser_callback_t callback = nullptr;
/// whether to throw exceptions in case of errors
const bool allow_exceptions = true;
/// a discarded value for the callback
BasicJsonType discarded = BasicJsonType::value_t::discarded;
};
template
class json_sax_acceptor
{
public:
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using number_float_t = typename BasicJsonType::number_float_t;
using string_t = typename BasicJsonType::string_t;
bool null()
{
return true;
}
bool boolean(bool /*unused*/)
{
return true;
}
bool number_integer(number_integer_t /*unused*/)
{
return true;
}
bool number_unsigned(number_unsigned_t /*unused*/)
{
return true;
}
bool number_float(number_float_t /*unused*/, const string_t& /*unused*/)
{
return true;
}
bool string(string_t& /*unused*/)
{
return true;
}
bool start_object(std::size_t /*unused*/ = std::size_t(-1))
{
return true;
}
bool key(string_t& /*unused*/)
{
return true;
}
bool end_object()
{
return true;
}
bool start_array(std::size_t /*unused*/ = std::size_t(-1))
{
return true;
}
bool end_array()
{
return true;
}
bool parse_error(std::size_t /*unused*/, const std::string& /*unused*/, const detail::exception& /*unused*/)
{
return false;
}
};
} // namespace detail
} // namespace nlohmann
// #include
// #include
namespace nlohmann
{
namespace detail
{
////////////
// parser //
////////////
/*!
@brief syntax analysis
This class implements a recursive decent parser.
*/
template
class parser
{
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using number_float_t = typename BasicJsonType::number_float_t;
using string_t = typename BasicJsonType::string_t;
using lexer_t = lexer;
using token_type = typename lexer_t::token_type;
public:
enum class parse_event_t : uint8_t
{
/// the parser read `{` and started to process a JSON object
object_start,
/// the parser read `}` and finished processing a JSON object
object_end,
/// the parser read `[` and started to process a JSON array
array_start,
/// the parser read `]` and finished processing a JSON array
array_end,
/// the parser read a key of a value in an object
key,
/// the parser finished reading a JSON value
value
};
using parser_callback_t =
std::function;
/// a parser reading from an input adapter
explicit parser(detail::input_adapter_t&& adapter,
const parser_callback_t cb = nullptr,
const bool allow_exceptions_ = true)
: callback(cb), m_lexer(std::move(adapter)), allow_exceptions(allow_exceptions_)
{
// read first token
get_token();
}
/*!
@brief public parser interface
@param[in] strict whether to expect the last token to be EOF
@param[in,out] result parsed JSON value
@throw parse_error.101 in case of an unexpected token
@throw parse_error.102 if to_unicode fails or surrogate error
@throw parse_error.103 if to_unicode fails
*/
void parse(const bool strict, BasicJsonType& result)
{
if (callback)
{
json_sax_dom_callback_parser sdp(result, callback, allow_exceptions);
sax_parse_internal(&sdp);
result.assert_invariant();
// in strict mode, input must be completely read
if (strict and (get_token() != token_type::end_of_input))
{
sdp.parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::end_of_input, “value”)));
}
// in case of an error, return discarded value
if (sdp.is_errored())
{
result = value_t::discarded;
return;
}
// set top-level value to null if it was discarded by the callback
// function
if (result.is_discarded())
{
result = nullptr;
}
}
else
{
json_sax_dom_parser sdp(result, allow_exceptions);
sax_parse_internal(&sdp);
result.assert_invariant();
// in strict mode, input must be completely read
if (strict and (get_token() != token_type::end_of_input))
{
sdp.parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::end_of_input, “value”)));
}
// in case of an error, return discarded value
if (sdp.is_errored())
{
result = value_t::discarded;
return;
}
}
}
/*!
@brief public accept interface
@param[in] strict whether to expect the last token to be EOF
@return whether the input is a proper JSON text
*/
bool accept(const bool strict = true)
{
json_sax_acceptor sax_acceptor;
return sax_parse(&sax_acceptor, strict);
}
template
bool sax_parse(SAX* sax, const bool strict = true)
{
(void)detail::is_sax_static_asserts {};
const bool result = sax_parse_internal(sax);
// strict mode: next byte must be EOF
if (result and strict and (get_token() != token_type::end_of_input))
{
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::end_of_input, “value”)));
}
return result;
}
private:
template
bool sax_parse_internal(SAX* sax)
{
// stack to remember the hierarchy of structured values we are parsing
// true = array; false = object
std::vector states;
// value to avoid a goto (see comment where set to true)
bool skip_to_state_evaluation = false;
while (true)
{
if (not skip_to_state_evaluation)
{
// invariant: get_token() was called before each iteration
switch (last_token)
{
case token_type::begin_object:
{
if (JSON_UNLIKELY(not sax->start_object(std::size_t(-1))))
{
return false;
}
// closing } -> we are done
if (get_token() == token_type::end_object)
{
if (JSON_UNLIKELY(not sax->end_object()))
{
return false;
}
break;
}
// parse key
if (JSON_UNLIKELY(last_token != token_type::value_string))
{
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::value_string, “object key”)));
}
if (JSON_UNLIKELY(not sax->key(m_lexer.get_string())))
{
return false;
}
// parse separator (:)
if (JSON_UNLIKELY(get_token() != token_type::name_separator))
{
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::name_separator, “object separator”)));
}
// remember we are now inside an object
states.push_back(false);
// parse values
get_token();
continue;
}
case token_type::begin_array:
{
if (JSON_UNLIKELY(not sax->start_array(std::size_t(-1))))
{
return false;
}
// closing ] -> we are done
if (get_token() == token_type::end_array)
{
if (JSON_UNLIKELY(not sax->end_array()))
{
return false;
}
break;
}
// remember we are now inside an array
states.push_back(true);
// parse values (no need to call get_token)
continue;
}
case token_type::value_float:
{
const auto res = m_lexer.get_number_float();
if (JSON_UNLIKELY(not std::isfinite(res)))
{
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
out_of_range::create(406, “number overflow parsing ‘” + m_lexer.get_token_string() + “‘”));
}
else
{
if (JSON_UNLIKELY(not sax->number_float(res, m_lexer.get_string())))
{
return false;
}
break;
}
}
case token_type::literal_false:
{
if (JSON_UNLIKELY(not sax->boolean(false)))
{
return false;
}
break;
}
case token_type::literal_null:
{
if (JSON_UNLIKELY(not sax->null()))
{
return false;
}
break;
}
case token_type::literal_true:
{
if (JSON_UNLIKELY(not sax->boolean(true)))
{
return false;
}
break;
}
case token_type::value_integer:
{
if (JSON_UNLIKELY(not sax->number_integer(m_lexer.get_number_integer())))
{
return false;
}
break;
}
case token_type::value_string:
{
if (JSON_UNLIKELY(not sax->string(m_lexer.get_string())))
{
return false;
}
break;
}
case token_type::value_unsigned:
{
if (JSON_UNLIKELY(not sax->number_unsigned(m_lexer.get_number_unsigned())))
{
return false;
}
break;
}
case token_type::parse_error:
{
// using “uninitialized” to avoid “expected” message
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::uninitialized, “value”)));
}
default: // the last token was unexpected
{
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::literal_or_value, “value”)));
}
}
}
else
{
skip_to_state_evaluation = false;
}
// we reached this line after we successfully parsed a value
if (states.empty())
{
// empty stack: we reached the end of the hierarchy: done
return true;
}
else
{
if (states.back()) // array
{
// comma -> next value
if (get_token() == token_type::value_separator)
{
// parse a new value
get_token();
continue;
}
// closing ]
if (JSON_LIKELY(last_token == token_type::end_array))
{
if (JSON_UNLIKELY(not sax->end_array()))
{
return false;
}
// We are done with this array. Before we can parse a
// new value, we need to evaluate the new state first.
// By setting skip_to_state_evaluation to false, we
// are effectively jumping to the beginning of this if.
assert(not states.empty());
states.pop_back();
skip_to_state_evaluation = true;
continue;
}
else
{
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::end_array, “array”)));
}
}
else // object
{
// comma -> next value
if (get_token() == token_type::value_separator)
{
// parse key
if (JSON_UNLIKELY(get_token() != token_type::value_string))
{
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::value_string, “object key”)));
}
else
{
if (JSON_UNLIKELY(not sax->key(m_lexer.get_string())))
{
return false;
}
}
// parse separator (:)
if (JSON_UNLIKELY(get_token() != token_type::name_separator))
{
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::name_separator, “object separator”)));
}
// parse values
get_token();
continue;
}
// closing }
if (JSON_LIKELY(last_token == token_type::end_object))
{
if (JSON_UNLIKELY(not sax->end_object()))
{
return false;
}
// We are done with this object. Before we can parse a
// new value, we need to evaluate the new state first.
// By setting skip_to_state_evaluation to false, we
// are effectively jumping to the beginning of this if.
assert(not states.empty());
states.pop_back();
skip_to_state_evaluation = true;
continue;
}
else
{
return sax->parse_error(m_lexer.get_position(),
m_lexer.get_token_string(),
parse_error::create(101, m_lexer.get_position(),
exception_message(token_type::end_object, “object”)));
}
}
}
}
}
/// get next token from lexer
token_type get_token()
{
return (last_token = m_lexer.scan());
}
std::string exception_message(const token_type expected, const std::string& context)
{
std::string error_msg = “syntax error “;
if (not context.empty())
{
error_msg += “while parsing ” + context + ” “;
}
error_msg += “- “;
if (last_token == token_type::parse_error)
{
error_msg += std::string(m_lexer.get_error_message()) + “; last read: ‘” +
m_lexer.get_token_string() + “‘”;
}
else
{
error_msg += “unexpected ” + std::string(lexer_t::token_type_name(last_token));
}
if (expected != token_type::uninitialized)
{
error_msg += “; expected ” + std::string(lexer_t::token_type_name(expected));
}
return error_msg;
}
private:
/// callback function
const parser_callback_t callback = nullptr;
/// the type of the last read token
token_type last_token = token_type::uninitialized;
/// the lexer
lexer_t m_lexer;
/// whether to throw exceptions in case of errors
const bool allow_exceptions = true;
};
} // namespace detail
} // namespace nlohmann
// #include
#include // ptrdiff_t
#include // numeric_limits
namespace nlohmann
{
namespace detail
{
/*
@brief an iterator for primitive JSON types
This class models an iterator for primitive JSON types (boolean, number,
string). It’s only purpose is to allow the iterator/const_iterator classes
to “iterate” over primitive values. Internally, the iterator is modeled by
a `difference_type` variable. Value begin_value (`0`) models the begin,
end_value (`1`) models past the end.
*/
class primitive_iterator_t
{
private:
using difference_type = std::ptrdiff_t;
static constexpr difference_type begin_value = 0;
static constexpr difference_type end_value = begin_value + 1;
/// iterator as signed integer type
difference_type m_it = (std::numeric_limits::min)();
public:
constexpr difference_type get_value() const noexcept
{
return m_it;
}
/// set iterator to a defined beginning
void set_begin() noexcept
{
m_it = begin_value;
}
/// set iterator to a defined past the end
void set_end() noexcept
{
m_it = end_value;
}
/// return whether the iterator can be dereferenced
constexpr bool is_begin() const noexcept
{
return m_it == begin_value;
}
/// return whether the iterator is at end
constexpr bool is_end() const noexcept
{
return m_it == end_value;
}
friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
{
return lhs.m_it == rhs.m_it;
}
friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
{
return lhs.m_it < rhs.m_it;
}
primitive_iterator_t operator+(difference_type n) noexcept
{
auto result = *this;
result += n;
return result;
}
friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
{
return lhs.m_it - rhs.m_it;
}
primitive_iterator_t& operator++() noexcept
{
++m_it;
return *this;
}
primitive_iterator_t const operator++(int) noexcept
{
auto result = *this;
++m_it;
return result;
}
primitive_iterator_t& operator--() noexcept
{
--m_it;
return *this;
}
primitive_iterator_t const operator--(int) noexcept
{
auto result = *this;
--m_it;
return result;
}
primitive_iterator_t& operator+=(difference_type n) noexcept
{
m_it += n;
return *this;
}
primitive_iterator_t& operator-=(difference_type n) noexcept
{
m_it -= n;
return *this;
}
};
} // namespace detail
} // namespace nlohmann
// #include
// #include
namespace nlohmann
{
namespace detail
{
/*!
@brief an iterator value
@note This structure could easily be a union, but MSVC currently does not allow
unions members with complex constructors, see https://github.com/nlohmann/json/pull/105.
*/
template struct internal_iterator
{
/// iterator for JSON objects
typename BasicJsonType::object_t::iterator object_iterator {};
/// iterator for JSON arrays
typename BasicJsonType::array_t::iterator array_iterator {};
/// generic iterator for all other types
primitive_iterator_t primitive_iterator {};
};
} // namespace detail
} // namespace nlohmann
// #include
#include // not
#include // iterator, random_access_iterator_tag, bidirectional_iterator_tag, advance, next
#include // conditional, is_const, remove_const
// #include
// #include
// #include
// #include
// #include
// #include
// #include
namespace nlohmann
{
namespace detail
{
// forward declare, to be able to friend it later on
template class iteration_proxy;
template class iteration_proxy_value;
/*!
@brief a template for a bidirectional iterator for the @ref basic_json class
This class implements a both iterators (iterator and const_iterator) for the
@ref basic_json class.
@note An iterator is called *initialized* when a pointer to a JSON value has
been set (e.g., by a constructor or a copy assignment). If the iterator is
default-constructed, it is *uninitialized* and most methods are undefined.
**The library uses assertions to detect calls on uninitialized iterators.**
@requirement The class satisfies the following concept requirements:
–
[BidirectionalIterator](https://en.cppreference.com/w/cpp/named_req/BidirectionalIterator):
The iterator that can be moved can be moved in both directions (i.e.
incremented and decremented).
@since version 1.0.0, simplified in version 2.0.9, change to bidirectional
iterators in version 3.0.0 (see https://github.com/nlohmann/json/issues/593)
*/
template
class iter_impl
{
/// allow basic_json to access private members
friend iter_impl::value, typename std::remove_const::type, const BasicJsonType>::type>;
friend BasicJsonType;
friend iteration_proxy;
friend iteration_proxy_value;
using object_t = typename BasicJsonType::object_t;
using array_t = typename BasicJsonType::array_t;
// make sure BasicJsonType is basic_json or const basic_json
static_assert(is_basic_json::type>::value,
“iter_impl only accepts (const) basic_json”);
public:
/// The std::iterator class template (used as a base class to provide typedefs) is deprecated in C++17.
/// The C++ Standard has never required user-defined iterators to derive from std::iterator.
/// A user-defined iterator should provide publicly accessible typedefs named
/// iterator_category, value_type, difference_type, pointer, and reference.
/// Note that value_type is required to be non-const, even for constant iterators.
using iterator_category = std::bidirectional_iterator_tag;
/// the type of the values when the iterator is dereferenced
using value_type = typename BasicJsonType::value_type;
/// a type to represent differences between iterators
using difference_type = typename BasicJsonType::difference_type;
/// defines a pointer to the type iterated over (value_type)
using pointer = typename std::conditional::value,
typename BasicJsonType::const_pointer,
typename BasicJsonType::pointer>::type;
/// defines a reference to the type iterated over (value_type)
using reference =
typename std::conditional::value,
typename BasicJsonType::const_reference,
typename BasicJsonType::reference>::type;
/// default constructor
iter_impl() = default;
/*!
@brief constructor for a given JSON instance
@param[in] object pointer to a JSON object for this iterator
@pre object != nullptr
@post The iterator is initialized; i.e. `m_object != nullptr`.
*/
explicit iter_impl(pointer object) noexcept : m_object(object)
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
{
m_it.object_iterator = typename object_t::iterator();
break;
}
case value_t::array:
{
m_it.array_iterator = typename array_t::iterator();
break;
}
default:
{
m_it.primitive_iterator = primitive_iterator_t();
break;
}
}
}
/*!
@note The conventional copy constructor and copy assignment are implicitly
defined. Combined with the following converting constructor and
assignment, they support: (1) copy from iterator to iterator, (2)
copy from const iterator to const iterator, and (3) conversion from
iterator to const iterator. However conversion from const iterator
to iterator is not defined.
*/
/*!
@brief converting constructor
@param[in] other non-const iterator to copy from
@note It is not checked whether @a other is initialized.
*/
iter_impl(const iter_impl::type>& other) noexcept
: m_object(other.m_object), m_it(other.m_it) {}
/*!
@brief converting assignment
@param[in,out] other non-const iterator to copy from
@return const/non-const iterator
@note It is not checked whether @a other is initialized.
*/
iter_impl& operator=(const iter_impl::type>& other) noexcept
{
m_object = other.m_object;
m_it = other.m_it;
return *this;
}
private:
/*!
@brief set the iterator to the first value
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
void set_begin() noexcept
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
{
m_it.object_iterator = m_object->m_value.object->begin();
break;
}
case value_t::array:
{
m_it.array_iterator = m_object->m_value.array->begin();
break;
}
case value_t::null:
{
// set to end so begin()==end() is true: null is empty
m_it.primitive_iterator.set_end();
break;
}
default:
{
m_it.primitive_iterator.set_begin();
break;
}
}
}
/*!
@brief set the iterator past the last value
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
void set_end() noexcept
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
{
m_it.object_iterator = m_object->m_value.object->end();
break;
}
case value_t::array:
{
m_it.array_iterator = m_object->m_value.array->end();
break;
}
default:
{
m_it.primitive_iterator.set_end();
break;
}
}
}
public:
/*!
@brief return a reference to the value pointed to by the iterator
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
reference operator*() const
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
{
assert(m_it.object_iterator != m_object->m_value.object->end());
return m_it.object_iterator->second;
}
case value_t::array:
{
assert(m_it.array_iterator != m_object->m_value.array->end());
return *m_it.array_iterator;
}
case value_t::null:
JSON_THROW(invalid_iterator::create(214, “cannot get value”));
default:
{
if (JSON_LIKELY(m_it.primitive_iterator.is_begin()))
{
return *m_object;
}
JSON_THROW(invalid_iterator::create(214, “cannot get value”));
}
}
}
/*!
@brief dereference the iterator
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
pointer operator->() const
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
{
assert(m_it.object_iterator != m_object->m_value.object->end());
return &(m_it.object_iterator->second);
}
case value_t::array:
{
assert(m_it.array_iterator != m_object->m_value.array->end());
return &*m_it.array_iterator;
}
default:
{
if (JSON_LIKELY(m_it.primitive_iterator.is_begin()))
{
return m_object;
}
JSON_THROW(invalid_iterator::create(214, “cannot get value”));
}
}
}
/*!
@brief post-increment (it++)
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
iter_impl const operator++(int)
{
auto result = *this;
++(*this);
return result;
}
/*!
@brief pre-increment (++it)
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
iter_impl& operator++()
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
{
std::advance(m_it.object_iterator, 1);
break;
}
case value_t::array:
{
std::advance(m_it.array_iterator, 1);
break;
}
default:
{
++m_it.primitive_iterator;
break;
}
}
return *this;
}
/*!
@brief post-decrement (it–)
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
iter_impl const operator–(int)
{
auto result = *this;
–(*this);
return result;
}
/*!
@brief pre-decrement (–it)
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
iter_impl& operator–()
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
{
std::advance(m_it.object_iterator, -1);
break;
}
case value_t::array:
{
std::advance(m_it.array_iterator, -1);
break;
}
default:
{
–m_it.primitive_iterator;
break;
}
}
return *this;
}
/*!
@brief comparison: equal
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
bool operator==(const iter_impl& other) const
{
// if objects are not the same, the comparison is undefined
if (JSON_UNLIKELY(m_object != other.m_object))
{
JSON_THROW(invalid_iterator::create(212, “cannot compare iterators of different containers”));
}
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
return (m_it.object_iterator == other.m_it.object_iterator);
case value_t::array:
return (m_it.array_iterator == other.m_it.array_iterator);
default:
return (m_it.primitive_iterator == other.m_it.primitive_iterator);
}
}
/*!
@brief comparison: not equal
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
bool operator!=(const iter_impl& other) const
{
return not operator==(other);
}
/*!
@brief comparison: smaller
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
bool operator<(const iter_impl& other) const
{
// if objects are not the same, the comparison is undefined
if (JSON_UNLIKELY(m_object != other.m_object))
{
JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers"));
}
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
JSON_THROW(invalid_iterator::create(213, “cannot compare order of object iterators”));
case value_t::array:
return (m_it.array_iterator < other.m_it.array_iterator);
default:
return (m_it.primitive_iterator < other.m_it.primitive_iterator);
}
}
/*!
@brief comparison: less than or equal
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
bool operator<=(const iter_impl& other) const
{
return not other.operator < (*this);
}
/*!
@brief comparison: greater than
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
bool operator>(const iter_impl& other) const
{
return not operator<=(other);
}
/*!
@brief comparison: greater than or equal
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
bool operator>=(const iter_impl& other) const
{
return not operator<(other);
}
/*!
@brief add to iterator
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
iter_impl& operator+=(difference_type i)
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
JSON_THROW(invalid_iterator::create(209, “cannot use offsets with object iterators”));
case value_t::array:
{
std::advance(m_it.array_iterator, i);
break;
}
default:
{
m_it.primitive_iterator += i;
break;
}
}
return *this;
}
/*!
@brief subtract from iterator
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
iter_impl& operator-=(difference_type i)
{
return operator+=(-i);
}
/*!
@brief add to iterator
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
iter_impl operator+(difference_type i) const
{
auto result = *this;
result += i;
return result;
}
/*!
@brief addition of distance and iterator
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
friend iter_impl operator+(difference_type i, const iter_impl& it)
{
auto result = it;
result += i;
return result;
}
/*!
@brief subtract from iterator
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
iter_impl operator-(difference_type i) const
{
auto result = *this;
result -= i;
return result;
}
/*!
@brief return difference
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
difference_type operator-(const iter_impl& other) const
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
JSON_THROW(invalid_iterator::create(209, “cannot use offsets with object iterators”));
case value_t::array:
return m_it.array_iterator – other.m_it.array_iterator;
default:
return m_it.primitive_iterator – other.m_it.primitive_iterator;
}
}
/*!
@brief access to successor
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
reference operator[](difference_type n) const
{
assert(m_object != nullptr);
switch (m_object->m_type)
{
case value_t::object:
JSON_THROW(invalid_iterator::create(208, “cannot use operator[] for object iterators”));
case value_t::array:
return *std::next(m_it.array_iterator, n);
case value_t::null:
JSON_THROW(invalid_iterator::create(214, “cannot get value”));
default:
{
if (JSON_LIKELY(m_it.primitive_iterator.get_value() == -n))
{
return *m_object;
}
JSON_THROW(invalid_iterator::create(214, “cannot get value”));
}
}
}
/*!
@brief return the key of an object iterator
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
const typename object_t::key_type& key() const
{
assert(m_object != nullptr);
if (JSON_LIKELY(m_object->is_object()))
{
return m_it.object_iterator->first;
}
JSON_THROW(invalid_iterator::create(207, “cannot use key() for non-object iterators”));
}
/*!
@brief return the value of an iterator
@pre The iterator is initialized; i.e. `m_object != nullptr`.
*/
reference value() const
{
return operator*();
}
private:
/// associated JSON instance
pointer m_object = nullptr;
/// the actual iterator of the associated instance
internal_iterator::type> m_it;
};
} // namespace detail
} // namespace nlohmann
// #include
// #include
#include // ptrdiff_t
#include // reverse_iterator
#include // declval
namespace nlohmann
{
namespace detail
{
//////////////////////
// reverse_iterator //
//////////////////////
/*!
@brief a template for a reverse iterator class
@tparam Base the base iterator type to reverse. Valid types are @ref
iterator (to create @ref reverse_iterator) and @ref const_iterator (to
create @ref const_reverse_iterator).
@requirement The class satisfies the following concept requirements:
–
[BidirectionalIterator](https://en.cppreference.com/w/cpp/named_req/BidirectionalIterator):
The iterator that can be moved can be moved in both directions (i.e.
incremented and decremented).
– [OutputIterator](https://en.cppreference.com/w/cpp/named_req/OutputIterator):
It is possible to write to the pointed-to element (only if @a Base is
@ref iterator).
@since version 1.0.0
*/
template
class json_reverse_iterator : public std::reverse_iterator
{
public:
using difference_type = std::ptrdiff_t;
/// shortcut to the reverse iterator adapter
using base_iterator = std::reverse_iterator;
/// the reference type for the pointed-to element
using reference = typename Base::reference;
/// create reverse iterator from iterator
explicit json_reverse_iterator(const typename base_iterator::iterator_type& it) noexcept
: base_iterator(it) {}
/// create reverse iterator from base class
explicit json_reverse_iterator(const base_iterator& it) noexcept : base_iterator(it) {}
/// post-increment (it++)
json_reverse_iterator const operator++(int)
{
return static_cast(base_iterator::operator++(1));
}
/// pre-increment (++it)
json_reverse_iterator& operator++()
{
return static_cast(base_iterator::operator++());
}
/// post-decrement (it–)
json_reverse_iterator const operator–(int)
{
return static_cast(base_iterator::operator–(1));
}
/// pre-decrement (–it)
json_reverse_iterator& operator–()
{
return static_cast(base_iterator::operator–());
}
/// add to iterator
json_reverse_iterator& operator+=(difference_type i)
{
return static_cast(base_iterator::operator+=(i));
}
/// add to iterator
json_reverse_iterator operator+(difference_type i) const
{
return static_cast(base_iterator::operator+(i));
}
/// subtract from iterator
json_reverse_iterator operator-(difference_type i) const
{
return static_cast(base_iterator::operator-(i));
}
/// return difference
difference_type operator-(const json_reverse_iterator& other) const
{
return base_iterator(*this) – base_iterator(other);
}
/// access to successor
reference operator[](difference_type n) const
{
return *(this->operator+(n));
}
/// return the key of an object iterator
auto key() const -> decltype(std::declval().key())
{
auto it = –this->base();
return it.key();
}
/// return the value of an iterator
reference value() const
{
auto it = –this->base();
return it.operator * ();
}
};
} // namespace detail
} // namespace nlohmann
// #include
#include // copy
#include // size_t
#include // streamsize
#include // back_inserter
#include // shared_ptr, make_shared
#include // basic_ostream
#include // basic_string
#include // vector
namespace nlohmann
{
namespace detail
{
/// abstract output adapter interface
template struct output_adapter_protocol
{
virtual void write_character(CharType c) = 0;
virtual void write_characters(const CharType* s, std::size_t length) = 0;
virtual ~output_adapter_protocol() = default;
};
/// a type to simplify interfaces
template
using output_adapter_t = std::shared_ptr>;
/// output adapter for byte vectors
template
class output_vector_adapter : public output_adapter_protocol
{
public:
explicit output_vector_adapter(std::vector& vec) noexcept
: v(vec)
{}
void write_character(CharType c) override
{
v.push_back(c);
}
void write_characters(const CharType* s, std::size_t length) override
{
std::copy(s, s + length, std::back_inserter(v));
}
private:
std::vector& v;
};
/// output adapter for output streams
template
class output_stream_adapter : public output_adapter_protocol
{
public:
explicit output_stream_adapter(std::basic_ostream& s) noexcept
: stream(s)
{}
void write_character(CharType c) override
{
stream.put(c);
}
void write_characters(const CharType* s, std::size_t length) override
{
stream.write(s, static_cast(length));
}
private:
std::basic_ostream& stream;
};
/// output adapter for basic_string
template>
class output_string_adapter : public output_adapter_protocol
{
public:
explicit output_string_adapter(StringType& s) noexcept
: str(s)
{}
void write_character(CharType c) override
{
str.push_back(c);
}
void write_characters(const CharType* s, std::size_t length) override
{
str.append(s, length);
}
private:
StringType& str;
};
template>
class output_adapter
{
public:
output_adapter(std::vector& vec)
: oa(std::make_shared>(vec)) {}
output_adapter(std::basic_ostream& s)
: oa(std::make_shared>(s)) {}
output_adapter(StringType& s)
: oa(std::make_shared>(s)) {}
operator output_adapter_t()
{
return oa;
}
private:
output_adapter_t oa = nullptr;
};
} // namespace detail
} // namespace nlohmann
// #include
#include // generate_n
#include // array
#include // assert
#include // ldexp
#include // size_t
#include // uint8_t, uint16_t, uint32_t, uint64_t
#include // snprintf
#include // memcpy
#include // back_inserter
#include // numeric_limits
#include // char_traits, string
#include // make_pair, move
// #include
// #include
// #include
// #include
// #include
// #include
namespace nlohmann
{
namespace detail
{
///////////////////
// binary reader //
///////////////////
/*!
@brief deserialization of CBOR, MessagePack, and UBJSON values
*/
template>
class binary_reader
{
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using number_float_t = typename BasicJsonType::number_float_t;
using string_t = typename BasicJsonType::string_t;
using json_sax_t = SAX;
public:
/*!
@brief create a binary reader
@param[in] adapter input adapter to read from
*/
explicit binary_reader(input_adapter_t adapter) : ia(std::move(adapter))
{
(void)detail::is_sax_static_asserts {};
assert(ia);
}
/*!
@param[in] format the binary format to parse
@param[in] sax_ a SAX event processor
@param[in] strict whether to expect the input to be consumed completed
@return
*/
bool sax_parse(const input_format_t format,
json_sax_t* sax_,
const bool strict = true)
{
sax = sax_;
bool result = false;
switch (format)
{
case input_format_t::bson:
result = parse_bson_internal();
break;
case input_format_t::cbor:
result = parse_cbor_internal();
break;
case input_format_t::msgpack:
result = parse_msgpack_internal();
break;
case input_format_t::ubjson:
result = parse_ubjson_internal();
break;
// LCOV_EXCL_START
default:
assert(false);
// LCOV_EXCL_STOP
}
// strict mode: next byte must be EOF
if (result and strict)
{
if (format == input_format_t::ubjson)
{
get_ignore_noop();
}
else
{
get();
}
if (JSON_UNLIKELY(current != std::char_traits::eof()))
{
return sax->parse_error(chars_read, get_token_string(),
parse_error::create(110, chars_read, exception_message(format, “expected end of input; last byte: 0x” + get_token_string(), “value”)));
}
}
return result;
}
/*!
@brief determine system byte order
@return true if and only if system’s byte order is little endian
@note from http://stackoverflow.com/a/1001328/266378
*/
static constexpr bool little_endianess(int num = 1) noexcept
{
return (*reinterpret_cast(&num) == 1);
}
private:
//////////
// BSON //
//////////
/*!
@brief Reads in a BSON-object and passes it to the SAX-parser.
@return whether a valid BSON-value was passed to the SAX parser
*/
bool parse_bson_internal()
{
std::int32_t document_size;
get_number(input_format_t::bson, document_size);
if (JSON_UNLIKELY(not sax->start_object(std::size_t(-1))))
{
return false;
}
if (JSON_UNLIKELY(not parse_bson_element_list(/*is_array*/false)))
{
return false;
}
return sax->end_object();
}
/*!
@brief Parses a C-style string from the BSON input.
@param[in, out] result A reference to the string variable where the read
string is to be stored.
@return `true` if the \x00-byte indicating the end of the string was
encountered before the EOF; false` indicates an unexpected EOF.
*/
bool get_bson_cstr(string_t& result)
{
auto out = std::back_inserter(result);
while (true)
{
get();
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::bson, “cstring”)))
{
return false;
}
if (current == 0x00)
{
return true;
}
*out++ = static_cast(current);
}
return true;
}
/*!
@brief Parses a zero-terminated string of length @a len from the BSON
input.
@param[in] len The length (including the zero-byte at the end) of the
string to be read.
@param[in, out] result A reference to the string variable where the read
string is to be stored.
@tparam NumberType The type of the length @a len
@pre len >= 1
@return `true` if the string was successfully parsed
*/
template
bool get_bson_string(const NumberType len, string_t& result)
{
if (JSON_UNLIKELY(len < 1))
{
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, exception_message(input_format_t::bson, “string length must be at least 1, is ” + std::to_string(len), “string”)));
}
return get_string(input_format_t::bson, len – static_cast(1), result) and get() != std::char_traits::eof();
}
/*!
@brief Read a BSON document element of the given @a element_type.
@param[in] element_type The BSON element type, c.f. http://bsonspec.org/spec.html
@param[in] element_type_parse_position The position in the input stream,
where the `element_type` was read.
@warning Not all BSON element types are supported yet. An unsupported
@a element_type will give rise to a parse_error.114:
Unsupported BSON record type 0x…
@return whether a valid BSON-object/array was passed to the SAX parser
*/
bool parse_bson_element_internal(const int element_type,
const std::size_t element_type_parse_position)
{
switch (element_type)
{
case 0x01: // double
{
double number;
return get_number(input_format_t::bson, number) and sax->number_float(static_cast(number), “”);
}
case 0x02: // string
{
std::int32_t len;
string_t value;
return get_number(input_format_t::bson, len) and get_bson_string(len, value) and sax->string(value);
}
case 0x03: // object
{
return parse_bson_internal();
}
case 0x04: // array
{
return parse_bson_array();
}
case 0x08: // boolean
{
return sax->boolean(get() != 0);
}
case 0x0A: // null
{
return sax->null();
}
case 0x10: // int32
{
std::int32_t value;
return get_number(input_format_t::bson, value) and sax->number_integer(value);
}
case 0x12: // int64
{
std::int64_t value;
return get_number(input_format_t::bson, value) and sax->number_integer(value);
}
default: // anything else not supported (yet)
{
char cr[3];
(std::snprintf)(cr, sizeof(cr), “%.2hhX”, static_cast(element_type));
return sax->parse_error(element_type_parse_position, std::string(cr), parse_error::create(114, element_type_parse_position, “Unsupported BSON record type 0x” + std::string(cr)));
}
}
}
/*!
@brief Read a BSON element list (as specified in the BSON-spec)
The same binary layout is used for objects and arrays, hence it must be
indicated with the argument @a is_array which one is expected
(true –> array, false –> object).
@param[in] is_array Determines if the element list being read is to be
treated as an object (@a is_array == false), or as an
array (@a is_array == true).
@return whether a valid BSON-object/array was passed to the SAX parser
*/
bool parse_bson_element_list(const bool is_array)
{
string_t key;
while (int element_type = get())
{
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::bson, “element list”)))
{
return false;
}
const std::size_t element_type_parse_position = chars_read;
if (JSON_UNLIKELY(not get_bson_cstr(key)))
{
return false;
}
if (not is_array)
{
if (not sax->key(key))
{
return false;
}
}
if (JSON_UNLIKELY(not parse_bson_element_internal(element_type, element_type_parse_position)))
{
return false;
}
// get_bson_cstr only appends
key.clear();
}
return true;
}
/*!
@brief Reads an array from the BSON input and passes it to the SAX-parser.
@return whether a valid BSON-array was passed to the SAX parser
*/
bool parse_bson_array()
{
std::int32_t document_size;
get_number(input_format_t::bson, document_size);
if (JSON_UNLIKELY(not sax->start_array(std::size_t(-1))))
{
return false;
}
if (JSON_UNLIKELY(not parse_bson_element_list(/*is_array*/true)))
{
return false;
}
return sax->end_array();
}
//////////
// CBOR //
//////////
/*!
@param[in] get_char whether a new character should be retrieved from the
input (true, default) or whether the last read
character should be considered instead
@return whether a valid CBOR value was passed to the SAX parser
*/
bool parse_cbor_internal(const bool get_char = true)
{
switch (get_char ? get() : current)
{
// EOF
case std::char_traits::eof():
return unexpect_eof(input_format_t::cbor, “value”);
// Integer 0x00..0x17 (0..23)
case 0x00:
case 0x01:
case 0x02:
case 0x03:
case 0x04:
case 0x05:
case 0x06:
case 0x07:
case 0x08:
case 0x09:
case 0x0A:
case 0x0B:
case 0x0C:
case 0x0D:
case 0x0E:
case 0x0F:
case 0x10:
case 0x11:
case 0x12:
case 0x13:
case 0x14:
case 0x15:
case 0x16:
case 0x17:
return sax->number_unsigned(static_cast(current));
case 0x18: // Unsigned integer (one-byte uint8_t follows)
{
uint8_t number;
return get_number(input_format_t::cbor, number) and sax->number_unsigned(number);
}
case 0x19: // Unsigned integer (two-byte uint16_t follows)
{
uint16_t number;
return get_number(input_format_t::cbor, number) and sax->number_unsigned(number);
}
case 0x1A: // Unsigned integer (four-byte uint32_t follows)
{
uint32_t number;
return get_number(input_format_t::cbor, number) and sax->number_unsigned(number);
}
case 0x1B: // Unsigned integer (eight-byte uint64_t follows)
{
uint64_t number;
return get_number(input_format_t::cbor, number) and sax->number_unsigned(number);
}
// Negative integer -1-0x00..-1-0x17 (-1..-24)
case 0x20:
case 0x21:
case 0x22:
case 0x23:
case 0x24:
case 0x25:
case 0x26:
case 0x27:
case 0x28:
case 0x29:
case 0x2A:
case 0x2B:
case 0x2C:
case 0x2D:
case 0x2E:
case 0x2F:
case 0x30:
case 0x31:
case 0x32:
case 0x33:
case 0x34:
case 0x35:
case 0x36:
case 0x37:
return sax->number_integer(static_cast(0x20 – 1 – current));
case 0x38: // Negative integer (one-byte uint8_t follows)
{
uint8_t number;
return get_number(input_format_t::cbor, number) and sax->number_integer(static_cast(-1) – number);
}
case 0x39: // Negative integer -1-n (two-byte uint16_t follows)
{
uint16_t number;
return get_number(input_format_t::cbor, number) and sax->number_integer(static_cast(-1) – number);
}
case 0x3A: // Negative integer -1-n (four-byte uint32_t follows)
{
uint32_t number;
return get_number(input_format_t::cbor, number) and sax->number_integer(static_cast(-1) – number);
}
case 0x3B: // Negative integer -1-n (eight-byte uint64_t follows)
{
uint64_t number;
return get_number(input_format_t::cbor, number) and sax->number_integer(static_cast(-1)
– static_cast(number));
}
// UTF-8 string (0x00..0x17 bytes follow)
case 0x60:
case 0x61:
case 0x62:
case 0x63:
case 0x64:
case 0x65:
case 0x66:
case 0x67:
case 0x68:
case 0x69:
case 0x6A:
case 0x6B:
case 0x6C:
case 0x6D:
case 0x6E:
case 0x6F:
case 0x70:
case 0x71:
case 0x72:
case 0x73:
case 0x74:
case 0x75:
case 0x76:
case 0x77:
case 0x78: // UTF-8 string (one-byte uint8_t for n follows)
case 0x79: // UTF-8 string (two-byte uint16_t for n follow)
case 0x7A: // UTF-8 string (four-byte uint32_t for n follow)
case 0x7B: // UTF-8 string (eight-byte uint64_t for n follow)
case 0x7F: // UTF-8 string (indefinite length)
{
string_t s;
return get_cbor_string(s) and sax->string(s);
}
// array (0x00..0x17 data items follow)
case 0x80:
case 0x81:
case 0x82:
case 0x83:
case 0x84:
case 0x85:
case 0x86:
case 0x87:
case 0x88:
case 0x89:
case 0x8A:
case 0x8B:
case 0x8C:
case 0x8D:
case 0x8E:
case 0x8F:
case 0x90:
case 0x91:
case 0x92:
case 0x93:
case 0x94:
case 0x95:
case 0x96:
case 0x97:
return get_cbor_array(static_cast(current & 0x1F));
case 0x98: // array (one-byte uint8_t for n follows)
{
uint8_t len;
return get_number(input_format_t::cbor, len) and get_cbor_array(static_cast(len));
}
case 0x99: // array (two-byte uint16_t for n follow)
{
uint16_t len;
return get_number(input_format_t::cbor, len) and get_cbor_array(static_cast(len));
}
case 0x9A: // array (four-byte uint32_t for n follow)
{
uint32_t len;
return get_number(input_format_t::cbor, len) and get_cbor_array(static_cast(len));
}
case 0x9B: // array (eight-byte uint64_t for n follow)
{
uint64_t len;
return get_number(input_format_t::cbor, len) and get_cbor_array(static_cast(len));
}
case 0x9F: // array (indefinite length)
return get_cbor_array(std::size_t(-1));
// map (0x00..0x17 pairs of data items follow)
case 0xA0:
case 0xA1:
case 0xA2:
case 0xA3:
case 0xA4:
case 0xA5:
case 0xA6:
case 0xA7:
case 0xA8:
case 0xA9:
case 0xAA:
case 0xAB:
case 0xAC:
case 0xAD:
case 0xAE:
case 0xAF:
case 0xB0:
case 0xB1:
case 0xB2:
case 0xB3:
case 0xB4:
case 0xB5:
case 0xB6:
case 0xB7:
return get_cbor_object(static_cast(current & 0x1F));
case 0xB8: // map (one-byte uint8_t for n follows)
{
uint8_t len;
return get_number(input_format_t::cbor, len) and get_cbor_object(static_cast(len));
}
case 0xB9: // map (two-byte uint16_t for n follow)
{
uint16_t len;
return get_number(input_format_t::cbor, len) and get_cbor_object(static_cast(len));
}
case 0xBA: // map (four-byte uint32_t for n follow)
{
uint32_t len;
return get_number(input_format_t::cbor, len) and get_cbor_object(static_cast(len));
}
case 0xBB: // map (eight-byte uint64_t for n follow)
{
uint64_t len;
return get_number(input_format_t::cbor, len) and get_cbor_object(static_cast(len));
}
case 0xBF: // map (indefinite length)
return get_cbor_object(std::size_t(-1));
case 0xF4: // false
return sax->boolean(false);
case 0xF5: // true
return sax->boolean(true);
case 0xF6: // null
return sax->null();
case 0xF9: // Half-Precision Float (two-byte IEEE 754)
{
const int byte1_raw = get();
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::cbor, “number”)))
{
return false;
}
const int byte2_raw = get();
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::cbor, “number”)))
{
return false;
}
const auto byte1 = static_cast(byte1_raw);
const auto byte2 = static_cast(byte2_raw);
// code from RFC 7049, Appendix D, Figure 3:
// As half-precision floating-point numbers were only added
// to IEEE 754 in 2008, today’s programming platforms often
// still only have limited support for them. It is very
// easy to include at least decoding support for them even
// without such support. An example of a small decoder for
// half-precision floating-point numbers in the C language
// is shown in Fig. 3.
const int half = (byte1 << 8) + byte2;
const double val = [&half]
{
const int exp = (half >> 10) & 0x1F;
const int mant = half & 0x3FF;
assert(0 <= exp and exp <= 32);
assert(0 <= mant and mant <= 1024);
switch (exp)
{
case 0:
return std::ldexp(mant, -24);
case 31:
return (mant == 0)
? std::numeric_limits::infinity()
: std::numeric_limits::quiet_NaN();
default:
return std::ldexp(mant + 1024, exp – 25);
}
}();
return sax->number_float((half & 0x8000) != 0
? static_cast(-val)
: static_cast(val), “”);
}
case 0xFA: // Single-Precision Float (four-byte IEEE 754)
{
float number;
return get_number(input_format_t::cbor, number) and sax->number_float(static_cast(number), “”);
}
case 0xFB: // Double-Precision Float (eight-byte IEEE 754)
{
double number;
return get_number(input_format_t::cbor, number) and sax->number_float(static_cast(number), “”);
}
default: // anything else (0xFF is handled inside the other types)
{
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, exception_message(input_format_t::cbor, “invalid byte: 0x” + last_token, “value”)));
}
}
}
/*!
@brief reads a CBOR string
This function first reads starting bytes to determine the expected
string length and then copies this number of bytes into a string.
Additionally, CBOR’s strings with indefinite lengths are supported.
@param[out] result created string
@return whether string creation completed
*/
bool get_cbor_string(string_t& result)
{
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::cbor, “string”)))
{
return false;
}
switch (current)
{
// UTF-8 string (0x00..0x17 bytes follow)
case 0x60:
case 0x61:
case 0x62:
case 0x63:
case 0x64:
case 0x65:
case 0x66:
case 0x67:
case 0x68:
case 0x69:
case 0x6A:
case 0x6B:
case 0x6C:
case 0x6D:
case 0x6E:
case 0x6F:
case 0x70:
case 0x71:
case 0x72:
case 0x73:
case 0x74:
case 0x75:
case 0x76:
case 0x77:
{
return get_string(input_format_t::cbor, current & 0x1F, result);
}
case 0x78: // UTF-8 string (one-byte uint8_t for n follows)
{
uint8_t len;
return get_number(input_format_t::cbor, len) and get_string(input_format_t::cbor, len, result);
}
case 0x79: // UTF-8 string (two-byte uint16_t for n follow)
{
uint16_t len;
return get_number(input_format_t::cbor, len) and get_string(input_format_t::cbor, len, result);
}
case 0x7A: // UTF-8 string (four-byte uint32_t for n follow)
{
uint32_t len;
return get_number(input_format_t::cbor, len) and get_string(input_format_t::cbor, len, result);
}
case 0x7B: // UTF-8 string (eight-byte uint64_t for n follow)
{
uint64_t len;
return get_number(input_format_t::cbor, len) and get_string(input_format_t::cbor, len, result);
}
case 0x7F: // UTF-8 string (indefinite length)
{
while (get() != 0xFF)
{
string_t chunk;
if (not get_cbor_string(chunk))
{
return false;
}
result.append(chunk);
}
return true;
}
default:
{
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, exception_message(input_format_t::cbor, “expected length specification (0x60-0x7B) or indefinite string type (0x7F); last byte: 0x” + last_token, “string”)));
}
}
}
/*!
@param[in] len the length of the array or std::size_t(-1) for an
array of indefinite size
@return whether array creation completed
*/
bool get_cbor_array(const std::size_t len)
{
if (JSON_UNLIKELY(not sax->start_array(len)))
{
return false;
}
if (len != std::size_t(-1))
{
for (std::size_t i = 0; i < len; ++i)
{
if (JSON_UNLIKELY(not parse_cbor_internal()))
{
return false;
}
}
}
else
{
while (get() != 0xFF)
{
if (JSON_UNLIKELY(not parse_cbor_internal(false)))
{
return false;
}
}
}
return sax->end_array();
}
/*!
@param[in] len the length of the object or std::size_t(-1) for an
object of indefinite size
@return whether object creation completed
*/
bool get_cbor_object(const std::size_t len)
{
if (JSON_UNLIKELY(not sax->start_object(len)))
{
return false;
}
string_t key;
if (len != std::size_t(-1))
{
for (std::size_t i = 0; i < len; ++i)
{
get();
if (JSON_UNLIKELY(not get_cbor_string(key) or not sax->key(key)))
{
return false;
}
if (JSON_UNLIKELY(not parse_cbor_internal()))
{
return false;
}
key.clear();
}
}
else
{
while (get() != 0xFF)
{
if (JSON_UNLIKELY(not get_cbor_string(key) or not sax->key(key)))
{
return false;
}
if (JSON_UNLIKELY(not parse_cbor_internal()))
{
return false;
}
key.clear();
}
}
return sax->end_object();
}
/////////////
// MsgPack //
/////////////
/*!
@return whether a valid MessagePack value was passed to the SAX parser
*/
bool parse_msgpack_internal()
{
switch (get())
{
// EOF
case std::char_traits::eof():
return unexpect_eof(input_format_t::msgpack, “value”);
// positive fixint
case 0x00:
case 0x01:
case 0x02:
case 0x03:
case 0x04:
case 0x05:
case 0x06:
case 0x07:
case 0x08:
case 0x09:
case 0x0A:
case 0x0B:
case 0x0C:
case 0x0D:
case 0x0E:
case 0x0F:
case 0x10:
case 0x11:
case 0x12:
case 0x13:
case 0x14:
case 0x15:
case 0x16:
case 0x17:
case 0x18:
case 0x19:
case 0x1A:
case 0x1B:
case 0x1C:
case 0x1D:
case 0x1E:
case 0x1F:
case 0x20:
case 0x21:
case 0x22:
case 0x23:
case 0x24:
case 0x25:
case 0x26:
case 0x27:
case 0x28:
case 0x29:
case 0x2A:
case 0x2B:
case 0x2C:
case 0x2D:
case 0x2E:
case 0x2F:
case 0x30:
case 0x31:
case 0x32:
case 0x33:
case 0x34:
case 0x35:
case 0x36:
case 0x37:
case 0x38:
case 0x39:
case 0x3A:
case 0x3B:
case 0x3C:
case 0x3D:
case 0x3E:
case 0x3F:
case 0x40:
case 0x41:
case 0x42:
case 0x43:
case 0x44:
case 0x45:
case 0x46:
case 0x47:
case 0x48:
case 0x49:
case 0x4A:
case 0x4B:
case 0x4C:
case 0x4D:
case 0x4E:
case 0x4F:
case 0x50:
case 0x51:
case 0x52:
case 0x53:
case 0x54:
case 0x55:
case 0x56:
case 0x57:
case 0x58:
case 0x59:
case 0x5A:
case 0x5B:
case 0x5C:
case 0x5D:
case 0x5E:
case 0x5F:
case 0x60:
case 0x61:
case 0x62:
case 0x63:
case 0x64:
case 0x65:
case 0x66:
case 0x67:
case 0x68:
case 0x69:
case 0x6A:
case 0x6B:
case 0x6C:
case 0x6D:
case 0x6E:
case 0x6F:
case 0x70:
case 0x71:
case 0x72:
case 0x73:
case 0x74:
case 0x75:
case 0x76:
case 0x77:
case 0x78:
case 0x79:
case 0x7A:
case 0x7B:
case 0x7C:
case 0x7D:
case 0x7E:
case 0x7F:
return sax->number_unsigned(static_cast(current));
// fixmap
case 0x80:
case 0x81:
case 0x82:
case 0x83:
case 0x84:
case 0x85:
case 0x86:
case 0x87:
case 0x88:
case 0x89:
case 0x8A:
case 0x8B:
case 0x8C:
case 0x8D:
case 0x8E:
case 0x8F:
return get_msgpack_object(static_cast(current & 0x0F));
// fixarray
case 0x90:
case 0x91:
case 0x92:
case 0x93:
case 0x94:
case 0x95:
case 0x96:
case 0x97:
case 0x98:
case 0x99:
case 0x9A:
case 0x9B:
case 0x9C:
case 0x9D:
case 0x9E:
case 0x9F:
return get_msgpack_array(static_cast(current & 0x0F));
// fixstr
case 0xA0:
case 0xA1:
case 0xA2:
case 0xA3:
case 0xA4:
case 0xA5:
case 0xA6:
case 0xA7:
case 0xA8:
case 0xA9:
case 0xAA:
case 0xAB:
case 0xAC:
case 0xAD:
case 0xAE:
case 0xAF:
case 0xB0:
case 0xB1:
case 0xB2:
case 0xB3:
case 0xB4:
case 0xB5:
case 0xB6:
case 0xB7:
case 0xB8:
case 0xB9:
case 0xBA:
case 0xBB:
case 0xBC:
case 0xBD:
case 0xBE:
case 0xBF:
{
string_t s;
return get_msgpack_string(s) and sax->string(s);
}
case 0xC0: // nil
return sax->null();
case 0xC2: // false
return sax->boolean(false);
case 0xC3: // true
return sax->boolean(true);
case 0xCA: // float 32
{
float number;
return get_number(input_format_t::msgpack, number) and sax->number_float(static_cast(number), “”);
}
case 0xCB: // float 64
{
double number;
return get_number(input_format_t::msgpack, number) and sax->number_float(static_cast(number), “”);
}
case 0xCC: // uint 8
{
uint8_t number;
return get_number(input_format_t::msgpack, number) and sax->number_unsigned(number);
}
case 0xCD: // uint 16
{
uint16_t number;
return get_number(input_format_t::msgpack, number) and sax->number_unsigned(number);
}
case 0xCE: // uint 32
{
uint32_t number;
return get_number(input_format_t::msgpack, number) and sax->number_unsigned(number);
}
case 0xCF: // uint 64
{
uint64_t number;
return get_number(input_format_t::msgpack, number) and sax->number_unsigned(number);
}
case 0xD0: // int 8
{
int8_t number;
return get_number(input_format_t::msgpack, number) and sax->number_integer(number);
}
case 0xD1: // int 16
{
int16_t number;
return get_number(input_format_t::msgpack, number) and sax->number_integer(number);
}
case 0xD2: // int 32
{
int32_t number;
return get_number(input_format_t::msgpack, number) and sax->number_integer(number);
}
case 0xD3: // int 64
{
int64_t number;
return get_number(input_format_t::msgpack, number) and sax->number_integer(number);
}
case 0xD9: // str 8
case 0xDA: // str 16
case 0xDB: // str 32
{
string_t s;
return get_msgpack_string(s) and sax->string(s);
}
case 0xDC: // array 16
{
uint16_t len;
return get_number(input_format_t::msgpack, len) and get_msgpack_array(static_cast(len));
}
case 0xDD: // array 32
{
uint32_t len;
return get_number(input_format_t::msgpack, len) and get_msgpack_array(static_cast(len));
}
case 0xDE: // map 16
{
uint16_t len;
return get_number(input_format_t::msgpack, len) and get_msgpack_object(static_cast(len));
}
case 0xDF: // map 32
{
uint32_t len;
return get_number(input_format_t::msgpack, len) and get_msgpack_object(static_cast(len));
}
// negative fixint
case 0xE0:
case 0xE1:
case 0xE2:
case 0xE3:
case 0xE4:
case 0xE5:
case 0xE6:
case 0xE7:
case 0xE8:
case 0xE9:
case 0xEA:
case 0xEB:
case 0xEC:
case 0xED:
case 0xEE:
case 0xEF:
case 0xF0:
case 0xF1:
case 0xF2:
case 0xF3:
case 0xF4:
case 0xF5:
case 0xF6:
case 0xF7:
case 0xF8:
case 0xF9:
case 0xFA:
case 0xFB:
case 0xFC:
case 0xFD:
case 0xFE:
case 0xFF:
return sax->number_integer(static_cast(current));
default: // anything else
{
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, exception_message(input_format_t::msgpack, “invalid byte: 0x” + last_token, “value”)));
}
}
}
/*!
@brief reads a MessagePack string
This function first reads starting bytes to determine the expected
string length and then copies this number of bytes into a string.
@param[out] result created string
@return whether string creation completed
*/
bool get_msgpack_string(string_t& result)
{
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::msgpack, “string”)))
{
return false;
}
switch (current)
{
// fixstr
case 0xA0:
case 0xA1:
case 0xA2:
case 0xA3:
case 0xA4:
case 0xA5:
case 0xA6:
case 0xA7:
case 0xA8:
case 0xA9:
case 0xAA:
case 0xAB:
case 0xAC:
case 0xAD:
case 0xAE:
case 0xAF:
case 0xB0:
case 0xB1:
case 0xB2:
case 0xB3:
case 0xB4:
case 0xB5:
case 0xB6:
case 0xB7:
case 0xB8:
case 0xB9:
case 0xBA:
case 0xBB:
case 0xBC:
case 0xBD:
case 0xBE:
case 0xBF:
{
return get_string(input_format_t::msgpack, current & 0x1F, result);
}
case 0xD9: // str 8
{
uint8_t len;
return get_number(input_format_t::msgpack, len) and get_string(input_format_t::msgpack, len, result);
}
case 0xDA: // str 16
{
uint16_t len;
return get_number(input_format_t::msgpack, len) and get_string(input_format_t::msgpack, len, result);
}
case 0xDB: // str 32
{
uint32_t len;
return get_number(input_format_t::msgpack, len) and get_string(input_format_t::msgpack, len, result);
}
default:
{
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, exception_message(input_format_t::msgpack, “expected length specification (0xA0-0xBF, 0xD9-0xDB); last byte: 0x” + last_token, “string”)));
}
}
}
/*!
@param[in] len the length of the array
@return whether array creation completed
*/
bool get_msgpack_array(const std::size_t len)
{
if (JSON_UNLIKELY(not sax->start_array(len)))
{
return false;
}
for (std::size_t i = 0; i < len; ++i)
{
if (JSON_UNLIKELY(not parse_msgpack_internal()))
{
return false;
}
}
return sax->end_array();
}
/*!
@param[in] len the length of the object
@return whether object creation completed
*/
bool get_msgpack_object(const std::size_t len)
{
if (JSON_UNLIKELY(not sax->start_object(len)))
{
return false;
}
string_t key;
for (std::size_t i = 0; i < len; ++i)
{
get();
if (JSON_UNLIKELY(not get_msgpack_string(key) or not sax->key(key)))
{
return false;
}
if (JSON_UNLIKELY(not parse_msgpack_internal()))
{
return false;
}
key.clear();
}
return sax->end_object();
}
////////////
// UBJSON //
////////////
/*!
@param[in] get_char whether a new character should be retrieved from the
input (true, default) or whether the last read
character should be considered instead
@return whether a valid UBJSON value was passed to the SAX parser
*/
bool parse_ubjson_internal(const bool get_char = true)
{
return get_ubjson_value(get_char ? get_ignore_noop() : current);
}
/*!
@brief reads a UBJSON string
This function is either called after reading the ‘S’ byte explicitly
indicating a string, or in case of an object key where the ‘S’ byte can be
left out.
@param[out] result created string
@param[in] get_char whether a new character should be retrieved from the
input (true, default) or whether the last read
character should be considered instead
@return whether string creation completed
*/
bool get_ubjson_string(string_t& result, const bool get_char = true)
{
if (get_char)
{
get(); // TODO: may we ignore N here?
}
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::ubjson, “value”)))
{
return false;
}
switch (current)
{
case ‘U’:
{
uint8_t len;
return get_number(input_format_t::ubjson, len) and get_string(input_format_t::ubjson, len, result);
}
case ‘i’:
{
int8_t len;
return get_number(input_format_t::ubjson, len) and get_string(input_format_t::ubjson, len, result);
}
case ‘I’:
{
int16_t len;
return get_number(input_format_t::ubjson, len) and get_string(input_format_t::ubjson, len, result);
}
case ‘l’:
{
int32_t len;
return get_number(input_format_t::ubjson, len) and get_string(input_format_t::ubjson, len, result);
}
case ‘L’:
{
int64_t len;
return get_number(input_format_t::ubjson, len) and get_string(input_format_t::ubjson, len, result);
}
default:
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, exception_message(input_format_t::ubjson, “expected length type specification (U, i, I, l, L); last byte: 0x” + last_token, “string”)));
}
}
/*!
@param[out] result determined size
@return whether size determination completed
*/
bool get_ubjson_size_value(std::size_t& result)
{
switch (get_ignore_noop())
{
case ‘U’:
{
uint8_t number;
if (JSON_UNLIKELY(not get_number(input_format_t::ubjson, number)))
{
return false;
}
result = static_cast(number);
return true;
}
case ‘i’:
{
int8_t number;
if (JSON_UNLIKELY(not get_number(input_format_t::ubjson, number)))
{
return false;
}
result = static_cast(number);
return true;
}
case ‘I’:
{
int16_t number;
if (JSON_UNLIKELY(not get_number(input_format_t::ubjson, number)))
{
return false;
}
result = static_cast(number);
return true;
}
case ‘l’:
{
int32_t number;
if (JSON_UNLIKELY(not get_number(input_format_t::ubjson, number)))
{
return false;
}
result = static_cast(number);
return true;
}
case ‘L’:
{
int64_t number;
if (JSON_UNLIKELY(not get_number(input_format_t::ubjson, number)))
{
return false;
}
result = static_cast(number);
return true;
}
default:
{
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, exception_message(input_format_t::ubjson, “expected length type specification (U, i, I, l, L) after ‘#’; last byte: 0x” + last_token, “size”)));
}
}
}
/*!
@brief determine the type and size for a container
In the optimized UBJSON format, a type and a size can be provided to allow
for a more compact representation.
@param[out] result pair of the size and the type
@return whether pair creation completed
*/
bool get_ubjson_size_type(std::pair& result)
{
result.first = string_t::npos; // size
result.second = 0; // type
get_ignore_noop();
if (current == ‘$’)
{
result.second = get(); // must not ignore ‘N’, because ‘N’ maybe the type
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::ubjson, “type”)))
{
return false;
}
get_ignore_noop();
if (JSON_UNLIKELY(current != ‘#’))
{
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::ubjson, “value”)))
{
return false;
}
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, exception_message(input_format_t::ubjson, “expected ‘#’ after type information; last byte: 0x” + last_token, “size”)));
}
return get_ubjson_size_value(result.first);
}
else if (current == ‘#’)
{
return get_ubjson_size_value(result.first);
}
return true;
}
/*!
@param prefix the previously read or set type prefix
@return whether value creation completed
*/
bool get_ubjson_value(const int prefix)
{
switch (prefix)
{
case std::char_traits::eof(): // EOF
return unexpect_eof(input_format_t::ubjson, “value”);
case ‘T’: // true
return sax->boolean(true);
case ‘F’: // false
return sax->boolean(false);
case ‘Z’: // null
return sax->null();
case ‘U’:
{
uint8_t number;
return get_number(input_format_t::ubjson, number) and sax->number_unsigned(number);
}
case ‘i’:
{
int8_t number;
return get_number(input_format_t::ubjson, number) and sax->number_integer(number);
}
case ‘I’:
{
int16_t number;
return get_number(input_format_t::ubjson, number) and sax->number_integer(number);
}
case ‘l’:
{
int32_t number;
return get_number(input_format_t::ubjson, number) and sax->number_integer(number);
}
case ‘L’:
{
int64_t number;
return get_number(input_format_t::ubjson, number) and sax->number_integer(number);
}
case ‘d’:
{
float number;
return get_number(input_format_t::ubjson, number) and sax->number_float(static_cast(number), “”);
}
case ‘D’:
{
double number;
return get_number(input_format_t::ubjson, number) and sax->number_float(static_cast(number), “”);
}
case ‘C’: // char
{
get();
if (JSON_UNLIKELY(not unexpect_eof(input_format_t::ubjson, “char”)))
{
return false;
}
if (JSON_UNLIKELY(current > 127))
{
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, exception_message(input_format_t::ubjson, “byte after ‘C’ must be in range 0x00..0x7F; last byte: 0x” + last_token, “char”)));
}
string_t s(1, static_cast(current));
return sax->string(s);
}
case ‘S’: // string
{
string_t s;
return get_ubjson_string(s) and sax->string(s);
}
case ‘[‘: // array
return get_ubjson_array();
case ‘{‘: // object
return get_ubjson_object();
default: // anything else
{
auto last_token = get_token_string();
return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, exception_message(input_format_t::ubjson, “invalid byte: 0x” + last_token, “value”)));
}
}
}
/*!
@return whether array creation completed
*/
bool get_ubjson_array()
{
std::pair size_and_type;
if (JSON_UNLIKELY(not get_ubjson_size_type(size_and_type)))
{
return false;
}
if (size_and_type.first != string_t::npos)
{
if (JSON_UNLIKELY(not sax->start_array(size_and_type.first)))
{
return false;
}
if (size_and_type.second != 0)
{
if (size_and_type.second != ‘N’)
{
for (std::size_t i = 0; i < size_and_type.first; ++i)
{
if (JSON_UNLIKELY(not get_ubjson_value(size_and_type.second)))
{
return false;
}
}
}
}
else
{
for (std::size_t i = 0; i < size_and_type.first; ++i)
{
if (JSON_UNLIKELY(not parse_ubjson_internal()))
{
return false;
}
}
}
}
else
{
if (JSON_UNLIKELY(not sax->start_array(std::size_t(-1))))
{
return false;
}
while (current != ‘]’)
{
if (JSON_UNLIKELY(not parse_ubjson_internal(false)))
{
return false;
}
get_ignore_noop();
}
}
return sax->end_array();
}
/*!
@return whether object creation completed
*/
bool get_ubjson_object()
{
std::pair size_and_type;
if (JSON_UNLIKELY(not get_ubjson_size_type(size_and_type)))
{
return false;
}
string_t key;
if (size_and_type.first != string_t::npos)
{
if (JSON_UNLIKELY(not sax->start_object(size_and_type.first)))
{
return false;
}
if (size_and_type.second != 0)
{
for (std::size_t i = 0; i < size_and_type.first; ++i)
{
if (JSON_UNLIKELY(not get_ubjson_string(key) or not sax->key(key)))
{
return false;
}
if (JSON_UNLIKELY(not get_ubjson_value(size_and_type.second)))
{
return false;
}
key.clear();
}
}
else
{
for (std::size_t i = 0; i < size_and_type.first; ++i)
{
if (JSON_UNLIKELY(not get_ubjson_string(key) or not sax->key(key)))
{
return false;
}
if (JSON_UNLIKELY(not parse_ubjson_internal()))
{
return false;
}
key.clear();
}
}
}
else
{
if (JSON_UNLIKELY(not sax->start_object(std::size_t(-1))))
{
return false;
}
while (current != ‘}’)
{
if (JSON_UNLIKELY(not get_ubjson_string(key, false) or not sax->key(key)))
{
return false;
}
if (JSON_UNLIKELY(not parse_ubjson_internal()))
{
return false;
}
get_ignore_noop();
key.clear();
}
}
return sax->end_object();
}
///////////////////////
// Utility functions //
///////////////////////
/*!
@brief get next character from the input
This function provides the interface to the used input adapter. It does
not throw in case the input reached EOF, but returns a -‘ve valued
`std::char_traits::eof()` in that case.
@return character read from the input
*/
int get()
{
++chars_read;
return (current = ia->get_character());
}
/*!
@return character read from the input after ignoring all ‘N’ entries
*/
int get_ignore_noop()
{
do
{
get();
}
while (current == ‘N’);
return current;
}
/*
@brief read a number from the input
@tparam NumberType the type of the number
@param[in] format the current format (for diagnostics)
@param[out] result number of type @a NumberType
@return whether conversion completed
@note This function needs to respect the system’s endianess, because
bytes in CBOR, MessagePack, and UBJSON are stored in network order
(big endian) and therefore need reordering on little endian systems.
*/
template
bool get_number(const input_format_t format, NumberType& result)
{
// step 1: read input into array with system’s byte order
std::array vec;
for (std::size_t i = 0; i < sizeof(NumberType); ++i)
{
get();
if (JSON_UNLIKELY(not unexpect_eof(format, "number")))
{
return false;
}
// reverse byte order prior to conversion if necessary
if (is_little_endian && !InputIsLittleEndian)
{
vec[sizeof(NumberType) - i - 1] = static_cast(current);
}
else
{
vec[i] = static_cast(current); // LCOV_EXCL_LINE
}
}
// step 2: convert array into number of type T and return
std::memcpy(&result, vec.data(), sizeof(NumberType));
return true;
}
/*!
@brief create a string by reading characters from the input
@tparam NumberType the type of the number
@param[in] format the current format (for diagnostics)
@param[in] len number of characters to read
@param[out] result string created by reading @a len bytes
@return whether string creation completed
@note We can not reserve @a len bytes for the result, because @a len
may be too large. Usually, @ref unexpect_eof() detects the end of
the input before we run out of string memory.
*/
template
bool get_string(const input_format_t format,
const NumberType len,
string_t& result)
{
bool success = true;
std::generate_n(std::back_inserter(result), len, [this, &success, &format]()
{
get();
if (JSON_UNLIKELY(not unexpect_eof(format, “string”)))
{
success = false;
}
return static_cast(current);
});
return success;
}
/*!
@param[in] format the current format (for diagnostics)
@param[in] context further context information (for diagnostics)
@return whether the last read character is not EOF
*/
bool unexpect_eof(const input_format_t format, const char* context) const
{
if (JSON_UNLIKELY(current == std::char_traits::eof()))
{
return sax->parse_error(chars_read, ““,
parse_error::create(110, chars_read, exception_message(format, “unexpected end of input”, context)));
}
return true;
}
/*!
@return a string representation of the last read byte
*/
std::string get_token_string() const
{
char cr[3];
(std::snprintf)(cr, 3, “%.2hhX”, static_cast(current));
return std::string{cr};
}
/*!
@param[in] format the current format
@param[in] detail a detailed error message
@param[in] context further contect information
@return a message string to use in the parse_error exceptions
*/
std::string exception_message(const input_format_t format,
const std::string& detail,
const std::string& context) const
{
std::string error_msg = “syntax error while parsing “;
switch (format)
{
case input_format_t::cbor:
error_msg += “CBOR”;
break;
case input_format_t::msgpack:
error_msg += “MessagePack”;
break;
case input_format_t::ubjson:
error_msg += “UBJSON”;
break;
case input_format_t::bson:
error_msg += “BSON”;
break;
// LCOV_EXCL_START
default:
assert(false);
// LCOV_EXCL_STOP
}
return error_msg + ” ” + context + “: ” + detail;
}
private:
/// input adapter
input_adapter_t ia = nullptr;
/// the current character
int current = std::char_traits::eof();
/// the number of characters read
std::size_t chars_read = 0;
/// whether we can assume little endianess
const bool is_little_endian = little_endianess();
/// the SAX parser
json_sax_t* sax = nullptr;
};
} // namespace detail
} // namespace nlohmann
// #include
#include // reverse
#include // array
#include // uint8_t, uint16_t, uint32_t, uint64_t
#include // memcpy
#include // numeric_limits
// #include
// #include
namespace nlohmann
{
namespace detail
{
///////////////////
// binary writer //
///////////////////
/*!
@brief serialization to CBOR and MessagePack values
*/
template
class binary_writer
{
using string_t = typename BasicJsonType::string_t;
public:
/*!
@brief create a binary writer
@param[in] adapter output adapter to write to
*/
explicit binary_writer(output_adapter_t adapter) : oa(adapter)
{
assert(oa);
}
/*!
@param[in] j JSON value to serialize
@pre j.type() == value_t::object
*/
void write_bson(const BasicJsonType& j)
{
switch (j.type())
{
case value_t::object:
{
write_bson_object(*j.m_value.object);
break;
}
default:
{
JSON_THROW(type_error::create(317, “to serialize to BSON, top-level type must be object, but is ” + std::string(j.type_name())));
}
}
}
/*!
@param[in] j JSON value to serialize
*/
void write_cbor(const BasicJsonType& j)
{
switch (j.type())
{
case value_t::null:
{
oa->write_character(to_char_type(0xF6));
break;
}
case value_t::boolean:
{
oa->write_character(j.m_value.boolean
? to_char_type(0xF5)
: to_char_type(0xF4));
break;
}
case value_t::number_integer:
{
if (j.m_value.number_integer >= 0)
{
// CBOR does not differentiate between positive signed
// integers and unsigned integers. Therefore, we used the
// code from the value_t::number_unsigned case here.
if (j.m_value.number_integer <= 0x17)
{
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_integer <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x18));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_integer <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x19));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_integer <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x1A));
write_number(static_cast(j.m_value.number_integer));
}
else
{
oa->write_character(to_char_type(0x1B));
write_number(static_cast(j.m_value.number_integer));
}
}
else
{
// The conversions below encode the sign in the first
// byte, and the value is converted to a positive number.
const auto positive_number = -1 – j.m_value.number_integer;
if (j.m_value.number_integer >= -24)
{
write_number(static_cast(0x20 + positive_number));
}
else if (positive_number <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x38));
write_number(static_cast(positive_number));
}
else if (positive_number <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x39));
write_number(static_cast(positive_number));
}
else if (positive_number <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x3A));
write_number(static_cast(positive_number));
}
else
{
oa->write_character(to_char_type(0x3B));
write_number(static_cast(positive_number));
}
}
break;
}
case value_t::number_unsigned:
{
if (j.m_value.number_unsigned <= 0x17)
{
write_number(static_cast(j.m_value.number_unsigned));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x18));
write_number(static_cast(j.m_value.number_unsigned));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x19));
write_number(static_cast(j.m_value.number_unsigned));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x1A));
write_number(static_cast(j.m_value.number_unsigned));
}
else
{
oa->write_character(to_char_type(0x1B));
write_number(static_cast(j.m_value.number_unsigned));
}
break;
}
case value_t::number_float:
{
oa->write_character(get_cbor_float_prefix(j.m_value.number_float));
write_number(j.m_value.number_float);
break;
}
case value_t::string:
{
// step 1: write control byte and the string length
const auto N = j.m_value.string->size();
if (N <= 0x17)
{
write_number(static_cast(0x60 + N));
}
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x78));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x79));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x7A));
write_number(static_cast(N));
}
// LCOV_EXCL_START
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x7B));
write_number(static_cast(N));
}
// LCOV_EXCL_STOP
// step 2: write the string
oa->write_characters(
reinterpret_cast(j.m_value.string->c_str()),
j.m_value.string->size());
break;
}
case value_t::array:
{
// step 1: write control byte and the array size
const auto N = j.m_value.array->size();
if (N <= 0x17)
{
write_number(static_cast(0x80 + N));
}
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x98));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x99));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x9A));
write_number(static_cast(N));
}
// LCOV_EXCL_START
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0x9B));
write_number(static_cast(N));
}
// LCOV_EXCL_STOP
// step 2: write each element
for (const auto& el : *j.m_value.array)
{
write_cbor(el);
}
break;
}
case value_t::object:
{
// step 1: write control byte and the object size
const auto N = j.m_value.object->size();
if (N <= 0x17)
{
write_number(static_cast(0xA0 + N));
}
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0xB8));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0xB9));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0xBA));
write_number(static_cast(N));
}
// LCOV_EXCL_START
else if (N <= (std::numeric_limits::max)())
{
oa->write_character(to_char_type(0xBB));
write_number(static_cast(N));
}
// LCOV_EXCL_STOP
// step 2: write each element
for (const auto& el : *j.m_value.object)
{
write_cbor(el.first);
write_cbor(el.second);
}
break;
}
default:
break;
}
}
/*!
@param[in] j JSON value to serialize
*/
void write_msgpack(const BasicJsonType& j)
{
switch (j.type())
{
case value_t::null: // nil
{
oa->write_character(to_char_type(0xC0));
break;
}
case value_t::boolean: // true and false
{
oa->write_character(j.m_value.boolean
? to_char_type(0xC3)
: to_char_type(0xC2));
break;
}
case value_t::number_integer:
{
if (j.m_value.number_integer >= 0)
{
// MessagePack does not differentiate between positive
// signed integers and unsigned integers. Therefore, we used
// the code from the value_t::number_unsigned case here.
if (j.m_value.number_unsigned < 128)
{
// positive fixnum
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
// uint 8
oa->write_character(to_char_type(0xCC));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
// uint 16
oa->write_character(to_char_type(0xCD));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
// uint 32
oa->write_character(to_char_type(0xCE));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
// uint 64
oa->write_character(to_char_type(0xCF));
write_number(static_cast(j.m_value.number_integer));
}
}
else
{
if (j.m_value.number_integer >= -32)
{
// negative fixnum
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_integer >= (std::numeric_limits::min)() and
j.m_value.number_integer <= (std::numeric_limits::max)())
{
// int 8
oa->write_character(to_char_type(0xD0));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_integer >= (std::numeric_limits::min)() and
j.m_value.number_integer <= (std::numeric_limits::max)())
{
// int 16
oa->write_character(to_char_type(0xD1));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_integer >= (std::numeric_limits::min)() and
j.m_value.number_integer <= (std::numeric_limits::max)())
{
// int 32
oa->write_character(to_char_type(0xD2));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_integer >= (std::numeric_limits::min)() and
j.m_value.number_integer <= (std::numeric_limits::max)())
{
// int 64
oa->write_character(to_char_type(0xD3));
write_number(static_cast(j.m_value.number_integer));
}
}
break;
}
case value_t::number_unsigned:
{
if (j.m_value.number_unsigned < 128)
{
// positive fixnum
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
// uint 8
oa->write_character(to_char_type(0xCC));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
// uint 16
oa->write_character(to_char_type(0xCD));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
// uint 32
oa->write_character(to_char_type(0xCE));
write_number(static_cast(j.m_value.number_integer));
}
else if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
// uint 64
oa->write_character(to_char_type(0xCF));
write_number(static_cast(j.m_value.number_integer));
}
break;
}
case value_t::number_float:
{
oa->write_character(get_msgpack_float_prefix(j.m_value.number_float));
write_number(j.m_value.number_float);
break;
}
case value_t::string:
{
// step 1: write control byte and the string length
const auto N = j.m_value.string->size();
if (N <= 31)
{
// fixstr
write_number(static_cast(0xA0 | N));
}
else if (N <= (std::numeric_limits::max)())
{
// str 8
oa->write_character(to_char_type(0xD9));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
// str 16
oa->write_character(to_char_type(0xDA));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
// str 32
oa->write_character(to_char_type(0xDB));
write_number(static_cast(N));
}
// step 2: write the string
oa->write_characters(
reinterpret_cast(j.m_value.string->c_str()),
j.m_value.string->size());
break;
}
case value_t::array:
{
// step 1: write control byte and the array size
const auto N = j.m_value.array->size();
if (N <= 15)
{
// fixarray
write_number(static_cast(0x90 | N));
}
else if (N <= (std::numeric_limits::max)())
{
// array 16
oa->write_character(to_char_type(0xDC));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
// array 32
oa->write_character(to_char_type(0xDD));
write_number(static_cast(N));
}
// step 2: write each element
for (const auto& el : *j.m_value.array)
{
write_msgpack(el);
}
break;
}
case value_t::object:
{
// step 1: write control byte and the object size
const auto N = j.m_value.object->size();
if (N <= 15)
{
// fixmap
write_number(static_cast(0x80 | (N & 0xF)));
}
else if (N <= (std::numeric_limits::max)())
{
// map 16
oa->write_character(to_char_type(0xDE));
write_number(static_cast(N));
}
else if (N <= (std::numeric_limits::max)())
{
// map 32
oa->write_character(to_char_type(0xDF));
write_number(static_cast(N));
}
// step 2: write each element
for (const auto& el : *j.m_value.object)
{
write_msgpack(el.first);
write_msgpack(el.second);
}
break;
}
default:
break;
}
}
/*!
@param[in] j JSON value to serialize
@param[in] use_count whether to use ‘#’ prefixes (optimized format)
@param[in] use_type whether to use ‘$’ prefixes (optimized format)
@param[in] add_prefix whether prefixes need to be used for this value
*/
void write_ubjson(const BasicJsonType& j, const bool use_count,
const bool use_type, const bool add_prefix = true)
{
switch (j.type())
{
case value_t::null:
{
if (add_prefix)
{
oa->write_character(to_char_type(‘Z’));
}
break;
}
case value_t::boolean:
{
if (add_prefix)
{
oa->write_character(j.m_value.boolean
? to_char_type(‘T’)
: to_char_type(‘F’));
}
break;
}
case value_t::number_integer:
{
write_number_with_ubjson_prefix(j.m_value.number_integer, add_prefix);
break;
}
case value_t::number_unsigned:
{
write_number_with_ubjson_prefix(j.m_value.number_unsigned, add_prefix);
break;
}
case value_t::number_float:
{
write_number_with_ubjson_prefix(j.m_value.number_float, add_prefix);
break;
}
case value_t::string:
{
if (add_prefix)
{
oa->write_character(to_char_type(‘S’));
}
write_number_with_ubjson_prefix(j.m_value.string->size(), true);
oa->write_characters(
reinterpret_cast(j.m_value.string->c_str()),
j.m_value.string->size());
break;
}
case value_t::array:
{
if (add_prefix)
{
oa->write_character(to_char_type(‘[‘));
}
bool prefix_required = true;
if (use_type and not j.m_value.array->empty())
{
assert(use_count);
const CharType first_prefix = ubjson_prefix(j.front());
const bool same_prefix = std::all_of(j.begin() + 1, j.end(),
[this, first_prefix](const BasicJsonType & v)
{
return ubjson_prefix(v) == first_prefix;
});
if (same_prefix)
{
prefix_required = false;
oa->write_character(to_char_type(‘$’));
oa->write_character(first_prefix);
}
}
if (use_count)
{
oa->write_character(to_char_type(‘#’));
write_number_with_ubjson_prefix(j.m_value.array->size(), true);
}
for (const auto& el : *j.m_value.array)
{
write_ubjson(el, use_count, use_type, prefix_required);
}
if (not use_count)
{
oa->write_character(to_char_type(‘]’));
}
break;
}
case value_t::object:
{
if (add_prefix)
{
oa->write_character(to_char_type(‘{‘));
}
bool prefix_required = true;
if (use_type and not j.m_value.object->empty())
{
assert(use_count);
const CharType first_prefix = ubjson_prefix(j.front());
const bool same_prefix = std::all_of(j.begin(), j.end(),
[this, first_prefix](const BasicJsonType & v)
{
return ubjson_prefix(v) == first_prefix;
});
if (same_prefix)
{
prefix_required = false;
oa->write_character(to_char_type(‘$’));
oa->write_character(first_prefix);
}
}
if (use_count)
{
oa->write_character(to_char_type(‘#’));
write_number_with_ubjson_prefix(j.m_value.object->size(), true);
}
for (const auto& el : *j.m_value.object)
{
write_number_with_ubjson_prefix(el.first.size(), true);
oa->write_characters(
reinterpret_cast(el.first.c_str()),
el.first.size());
write_ubjson(el.second, use_count, use_type, prefix_required);
}
if (not use_count)
{
oa->write_character(to_char_type(‘}’));
}
break;
}
default:
break;
}
}
private:
//////////
// BSON //
//////////
/*!
@return The size of a BSON document entry header, including the id marker
and the entry name size (and its null-terminator).
*/
static std::size_t calc_bson_entry_header_size(const string_t& name)
{
const auto it = name.find(static_cast(0));
if (JSON_UNLIKELY(it != BasicJsonType::string_t::npos))
{
JSON_THROW(out_of_range::create(409,
“BSON key cannot contain code point U+0000 (at byte ” + std::to_string(it) + “)”));
}
return /*id*/ 1ul + name.size() + /*zero-terminator*/1u;
}
/*!
@brief Writes the given @a element_type and @a name to the output adapter
*/
void write_bson_entry_header(const string_t& name,
const std::uint8_t element_type)
{
oa->write_character(to_char_type(element_type)); // boolean
oa->write_characters(
reinterpret_cast(name.c_str()),
name.size() + 1u);
}
/*!
@brief Writes a BSON element with key @a name and boolean value @a value
*/
void write_bson_boolean(const string_t& name,
const bool value)
{
write_bson_entry_header(name, 0x08);
oa->write_character(value ? to_char_type(0x01) : to_char_type(0x00));
}
/*!
@brief Writes a BSON element with key @a name and double value @a value
*/
void write_bson_double(const string_t& name,
const double value)
{
write_bson_entry_header(name, 0x01);
write_number(value);
}
/*!
@return The size of the BSON-encoded string in @a value
*/
static std::size_t calc_bson_string_size(const string_t& value)
{
return sizeof(std::int32_t) + value.size() + 1ul;
}
/*!
@brief Writes a BSON element with key @a name and string value @a value
*/
void write_bson_string(const string_t& name,
const string_t& value)
{
write_bson_entry_header(name, 0x02);
write_number(static_cast(value.size() + 1ul));
oa->write_characters(
reinterpret_cast(value.c_str()),
value.size() + 1);
}
/*!
@brief Writes a BSON element with key @a name and null value
*/
void write_bson_null(const string_t& name)
{
write_bson_entry_header(name, 0x0A);
}
/*!
@return The size of the BSON-encoded integer @a value
*/
static std::size_t calc_bson_integer_size(const std::int64_t value)
{
if ((std::numeric_limits::min)() <= value and value <= (std::numeric_limits::max)())
{
return sizeof(std::int32_t);
}
else
{
return sizeof(std::int64_t);
}
}
/*!
@brief Writes a BSON element with key @a name and integer @a value
*/
void write_bson_integer(const string_t& name,
const std::int64_t value)
{
if ((std::numeric_limits::min)() <= value and value <= (std::numeric_limits::max)())
{
write_bson_entry_header(name, 0x10); // int32
write_number(static_cast(value));
}
else
{
write_bson_entry_header(name, 0x12); // int64
write_number(static_cast(value));
}
}
/*!
@return The size of the BSON-encoded unsigned integer in @a j
*/
static constexpr std::size_t calc_bson_unsigned_size(const std::uint64_t value) noexcept
{
return (value <= static_cast((std::numeric_limits::max)()))
? sizeof(std::int32_t)
: sizeof(std::int64_t);
}
/*!
@brief Writes a BSON element with key @a name and unsigned @a value
*/
void write_bson_unsigned(const string_t& name,
const std::uint64_t value)
{
if (value <= static_cast((std::numeric_limits::max)()))
{
write_bson_entry_header(name, 0x10 /* int32 */);
write_number(static_cast(value));
}
else if (value <= static_cast((std::numeric_limits::max)()))
{
write_bson_entry_header(name, 0x12 /* int64 */);
write_number(static_cast(value));
}
else
{
JSON_THROW(out_of_range::create(407, “integer number ” + std::to_string(value) + ” cannot be represented by BSON as it does not fit int64″));
}
}
/*!
@brief Writes a BSON element with key @a name and object @a value
*/
void write_bson_object_entry(const string_t& name,
const typename BasicJsonType::object_t& value)
{
write_bson_entry_header(name, 0x03); // object
write_bson_object(value);
}
/*!
@return The size of the BSON-encoded array @a value
*/
static std::size_t calc_bson_array_size(const typename BasicJsonType::array_t& value)
{
std::size_t embedded_document_size = 0ul;
std::size_t array_index = 0ul;
for (const auto& el : value)
{
embedded_document_size += calc_bson_element_size(std::to_string(array_index++), el);
}
return sizeof(std::int32_t) + embedded_document_size + 1ul;
}
/*!
@brief Writes a BSON element with key @a name and array @a value
*/
void write_bson_array(const string_t& name,
const typename BasicJsonType::array_t& value)
{
write_bson_entry_header(name, 0x04); // array
write_number(static_cast(calc_bson_array_size(value)));
std::size_t array_index = 0ul;
for (const auto& el : value)
{
write_bson_element(std::to_string(array_index++), el);
}
oa->write_character(to_char_type(0x00));
}
/*!
@brief Calculates the size necessary to serialize the JSON value @a j with its @a name
@return The calculated size for the BSON document entry for @a j with the given @a name.
*/
static std::size_t calc_bson_element_size(const string_t& name,
const BasicJsonType& j)
{
const auto header_size = calc_bson_entry_header_size(name);
switch (j.type())
{
case value_t::object:
return header_size + calc_bson_object_size(*j.m_value.object);
case value_t::array:
return header_size + calc_bson_array_size(*j.m_value.array);
case value_t::boolean:
return header_size + 1ul;
case value_t::number_float:
return header_size + 8ul;
case value_t::number_integer:
return header_size + calc_bson_integer_size(j.m_value.number_integer);
case value_t::number_unsigned:
return header_size + calc_bson_unsigned_size(j.m_value.number_unsigned);
case value_t::string:
return header_size + calc_bson_string_size(*j.m_value.string);
case value_t::null:
return header_size + 0ul;
// LCOV_EXCL_START
default:
assert(false);
return 0ul;
// LCOV_EXCL_STOP
}
}
/*!
@brief Serializes the JSON value @a j to BSON and associates it with the
key @a name.
@param name The name to associate with the JSON entity @a j within the
current BSON document
@return The size of the BSON entry
*/
void write_bson_element(const string_t& name,
const BasicJsonType& j)
{
switch (j.type())
{
case value_t::object:
return write_bson_object_entry(name, *j.m_value.object);
case value_t::array:
return write_bson_array(name, *j.m_value.array);
case value_t::boolean:
return write_bson_boolean(name, j.m_value.boolean);
case value_t::number_float:
return write_bson_double(name, j.m_value.number_float);
case value_t::number_integer:
return write_bson_integer(name, j.m_value.number_integer);
case value_t::number_unsigned:
return write_bson_unsigned(name, j.m_value.number_unsigned);
case value_t::string:
return write_bson_string(name, *j.m_value.string);
case value_t::null:
return write_bson_null(name);
// LCOV_EXCL_START
default:
assert(false);
return;
// LCOV_EXCL_STOP
}
}
/*!
@brief Calculates the size of the BSON serialization of the given
JSON-object @a j.
@param[in] j JSON value to serialize
@pre j.type() == value_t::object
*/
static std::size_t calc_bson_object_size(const typename BasicJsonType::object_t& value)
{
std::size_t document_size = std::accumulate(value.begin(), value.end(), 0ul,
[](size_t result, const typename BasicJsonType::object_t::value_type & el)
{
return result += calc_bson_element_size(el.first, el.second);
});
return sizeof(std::int32_t) + document_size + 1ul;
}
/*!
@param[in] j JSON value to serialize
@pre j.type() == value_t::object
*/
void write_bson_object(const typename BasicJsonType::object_t& value)
{
write_number(static_cast(calc_bson_object_size(value)));
for (const auto& el : value)
{
write_bson_element(el.first, el.second);
}
oa->write_character(to_char_type(0x00));
}
//////////
// CBOR //
//////////
static constexpr CharType get_cbor_float_prefix(float /*unused*/)
{
return to_char_type(0xFA); // Single-Precision Float
}
static constexpr CharType get_cbor_float_prefix(double /*unused*/)
{
return to_char_type(0xFB); // Double-Precision Float
}
/////////////
// MsgPack //
/////////////
static constexpr CharType get_msgpack_float_prefix(float /*unused*/)
{
return to_char_type(0xCA); // float 32
}
static constexpr CharType get_msgpack_float_prefix(double /*unused*/)
{
return to_char_type(0xCB); // float 64
}
////////////
// UBJSON //
////////////
// UBJSON: write number (floating point)
template::value, int>::type = 0>
void write_number_with_ubjson_prefix(const NumberType n,
const bool add_prefix)
{
if (add_prefix)
{
oa->write_character(get_ubjson_float_prefix(n));
}
write_number(n);
}
// UBJSON: write number (unsigned integer)
template::value, int>::type = 0>
void write_number_with_ubjson_prefix(const NumberType n,
const bool add_prefix)
{
if (n <= static_cast((std::numeric_limits::max)()))
{
if (add_prefix)
{
oa->write_character(to_char_type(‘i’)); // int8
}
write_number(static_cast(n));
}
else if (n <= (std::numeric_limits::max)())
{
if (add_prefix)
{
oa->write_character(to_char_type(‘U’)); // uint8
}
write_number(static_cast(n));
}
else if (n <= static_cast((std::numeric_limits::max)()))
{
if (add_prefix)
{
oa->write_character(to_char_type(‘I’)); // int16
}
write_number(static_cast(n));
}
else if (n <= static_cast((std::numeric_limits::max)()))
{
if (add_prefix)
{
oa->write_character(to_char_type(‘l’)); // int32
}
write_number(static_cast(n));
}
else if (n <= static_cast((std::numeric_limits::max)()))
{
if (add_prefix)
{
oa->write_character(to_char_type(‘L’)); // int64
}
write_number(static_cast(n));
}
else
{
JSON_THROW(out_of_range::create(407, “integer number ” + std::to_string(n) + ” cannot be represented by UBJSON as it does not fit int64″));
}
}
// UBJSON: write number (signed integer)
template::value and
not std::is_floating_point::value, int>::type = 0>
void write_number_with_ubjson_prefix(const NumberType n,
const bool add_prefix)
{
if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)())
{
if (add_prefix)
{
oa->write_character(to_char_type(‘i’)); // int8
}
write_number(static_cast(n));
}
else if (static_cast((std::numeric_limits::min)()) <= n and n <= static_cast((std::numeric_limits::max)()))
{
if (add_prefix)
{
oa->write_character(to_char_type(‘U’)); // uint8
}
write_number(static_cast(n));
}
else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)())
{
if (add_prefix)
{
oa->write_character(to_char_type(‘I’)); // int16
}
write_number(static_cast(n));
}
else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)())
{
if (add_prefix)
{
oa->write_character(to_char_type(‘l’)); // int32
}
write_number(static_cast(n));
}
else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)())
{
if (add_prefix)
{
oa->write_character(to_char_type(‘L’)); // int64
}
write_number(static_cast(n));
}
// LCOV_EXCL_START
else
{
JSON_THROW(out_of_range::create(407, “integer number ” + std::to_string(n) + ” cannot be represented by UBJSON as it does not fit int64″));
}
// LCOV_EXCL_STOP
}
/*!
@brief determine the type prefix of container values
@note This function does not need to be 100% accurate when it comes to
integer limits. In case a number exceeds the limits of int64_t,
this will be detected by a later call to function
write_number_with_ubjson_prefix. Therefore, we return ‘L’ for any
value that does not fit the previous limits.
*/
CharType ubjson_prefix(const BasicJsonType& j) const noexcept
{
switch (j.type())
{
case value_t::null:
return ‘Z’;
case value_t::boolean:
return j.m_value.boolean ? ‘T’ : ‘F’;
case value_t::number_integer:
{
if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)())
{
return ‘i’;
}
if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)())
{
return ‘U’;
}
if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)())
{
return ‘I’;
}
if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)())
{
return ‘l’;
}
// no check and assume int64_t (see note above)
return ‘L’;
}
case value_t::number_unsigned:
{
if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
return ‘i’;
}
if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
return ‘U’;
}
if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
return ‘I’;
}
if (j.m_value.number_unsigned <= (std::numeric_limits::max)())
{
return ‘l’;
}
// no check and assume int64_t (see note above)
return ‘L’;
}
case value_t::number_float:
return get_ubjson_float_prefix(j.m_value.number_float);
case value_t::string:
return ‘S’;
case value_t::array:
return ‘[‘;
case value_t::object:
return ‘{‘;
default: // discarded values
return ‘N’;
}
}
static constexpr CharType get_ubjson_float_prefix(float /*unused*/)
{
return ‘d’; // float 32
}
static constexpr CharType get_ubjson_float_prefix(double /*unused*/)
{
return ‘D’; // float 64
}
///////////////////////
// Utility functions //
///////////////////////
/*
@brief write a number to output input
@param[in] n number of type @a NumberType
@tparam NumberType the type of the number
@tparam OutputIsLittleEndian Set to true if output data is
required to be little endian
@note This function needs to respect the system’s endianess, because bytes
in CBOR, MessagePack, and UBJSON are stored in network order (big
endian) and therefore need reordering on little endian systems.
*/
template
void write_number(const NumberType n)
{
// step 1: write number to array of length NumberType
std::array vec;
std::memcpy(vec.data(), &n, sizeof(NumberType));
// step 2: write array to output (with possible reordering)
if (is_little_endian and not OutputIsLittleEndian)
{
// reverse byte order prior to conversion if necessary
std::reverse(vec.begin(), vec.end());
}
oa->write_characters(vec.data(), sizeof(NumberType));
}
public:
// The following to_char_type functions are implement the conversion
// between uint8_t and CharType. In case CharType is not unsigned,
// such a conversion is required to allow values greater than 128.
// See for a discussion.
template < typename C = CharType,
enable_if_t < std::is_signed::value and std::is_signed::value > * = nullptr >
static constexpr CharType to_char_type(std::uint8_t x) noexcept
{
return *reinterpret_cast(&x);
}
template < typename C = CharType,
enable_if_t < std::is_signed::value and std::is_unsigned::value > * = nullptr >
static CharType to_char_type(std::uint8_t x) noexcept
{
static_assert(sizeof(std::uint8_t) == sizeof(CharType), “size of CharType must be equal to std::uint8_t”);
static_assert(std::is_pod::value, “CharType must be POD”);
CharType result;
std::memcpy(&result, &x, sizeof(x));
return result;
}
template::value>* = nullptr>
static constexpr CharType to_char_type(std::uint8_t x) noexcept
{
return x;
}
template < typename InputCharType, typename C = CharType,
enable_if_t <
std::is_signed::value and
std::is_signed::value and
std::is_same::type>::value
> * = nullptr >
static constexpr CharType to_char_type(InputCharType x) noexcept
{
return x;
}
private:
/// whether we can assume little endianess
const bool is_little_endian = binary_reader::little_endianess();
/// the output
output_adapter_t oa = nullptr;
};
} // namespace detail
} // namespace nlohmann
// #include
#include // reverse, remove, fill, find, none_of
#include // array
#include // assert
#include // and, or
#include // localeconv, lconv
#include // labs, isfinite, isnan, signbit
#include // size_t, ptrdiff_t
#include // uint8_t
#include // snprintf
#include // numeric_limits
#include // string
#include // is_same
// #include
// #include
#include // assert
#include // or, and, not
#include // signbit, isfinite
#include // intN_t, uintN_t
#include // memcpy, memmove
#include // numeric_limits
#include // conditional
namespace nlohmann
{
namespace detail
{
/*!
@brief implements the Grisu2 algorithm for binary to decimal floating-point
conversion.
This implementation is a slightly modified version of the reference
implementation which may be obtained from
http://florian.loitsch.com/publications (bench.tar.gz).
The code is distributed under the MIT license, Copyright (c) 2009 Florian Loitsch.
For a detailed description of the algorithm see:
[1] Loitsch, “Printing Floating-Point Numbers Quickly and Accurately with
Integers”, Proceedings of the ACM SIGPLAN 2010 Conference on Programming
Language Design and Implementation, PLDI 2010
[2] Burger, Dybvig, “Printing Floating-Point Numbers Quickly and Accurately”,
Proceedings of the ACM SIGPLAN 1996 Conference on Programming Language
Design and Implementation, PLDI 1996
*/
namespace dtoa_impl
{
template
Target reinterpret_bits(const Source source)
{
static_assert(sizeof(Target) == sizeof(Source), “size mismatch”);
Target target;
std::memcpy(&target, &source, sizeof(Source));
return target;
}
struct diyfp // f * 2^e
{
static constexpr int kPrecision = 64; // = q
uint64_t f = 0;
int e = 0;
constexpr diyfp(uint64_t f_, int e_) noexcept : f(f_), e(e_) {}
/*!
@brief returns x – y
@pre x.e == y.e and x.f >= y.f
*/
static diyfp sub(const diyfp& x, const diyfp& y) noexcept
{
assert(x.e == y.e);
assert(x.f >= y.f);
return {x.f – y.f, x.e};
}
/*!
@brief returns x * y
@note The result is rounded. (Only the upper q bits are returned.)
*/
static diyfp mul(const diyfp& x, const diyfp& y) noexcept
{
static_assert(kPrecision == 64, “internal error”);
// Computes:
// f = round((x.f * y.f) / 2^q)
// e = x.e + y.e + q
// Emulate the 64-bit * 64-bit multiplication:
//
// p = u * v
// = (u_lo + 2^32 u_hi) (v_lo + 2^32 v_hi)
// = (u_lo v_lo ) + 2^32 ((u_lo v_hi ) + (u_hi v_lo )) + 2^64 (u_hi v_hi )
// = (p0 ) + 2^32 ((p1 ) + (p2 )) + 2^64 (p3 )
// = (p0_lo + 2^32 p0_hi) + 2^32 ((p1_lo + 2^32 p1_hi) + (p2_lo + 2^32 p2_hi)) + 2^64 (p3 )
// = (p0_lo ) + 2^32 (p0_hi + p1_lo + p2_lo ) + 2^64 (p1_hi + p2_hi + p3)
// = (p0_lo ) + 2^32 (Q ) + 2^64 (H )
// = (p0_lo ) + 2^32 (Q_lo + 2^32 Q_hi ) + 2^64 (H )
//
// (Since Q might be larger than 2^32 – 1)
//
// = (p0_lo + 2^32 Q_lo) + 2^64 (Q_hi + H)
//
// (Q_hi + H does not overflow a 64-bit int)
//
// = p_lo + 2^64 p_hi
const uint64_t u_lo = x.f & 0xFFFFFFFF;
const uint64_t u_hi = x.f >> 32;
const uint64_t v_lo = y.f & 0xFFFFFFFF;
const uint64_t v_hi = y.f >> 32;
const uint64_t p0 = u_lo * v_lo;
const uint64_t p1 = u_lo * v_hi;
const uint64_t p2 = u_hi * v_lo;
const uint64_t p3 = u_hi * v_hi;
const uint64_t p0_hi = p0 >> 32;
const uint64_t p1_lo = p1 & 0xFFFFFFFF;
const uint64_t p1_hi = p1 >> 32;
const uint64_t p2_lo = p2 & 0xFFFFFFFF;
const uint64_t p2_hi = p2 >> 32;
uint64_t Q = p0_hi + p1_lo + p2_lo;
// The full product might now be computed as
//
// p_hi = p3 + p2_hi + p1_hi + (Q >> 32)
// p_lo = p0_lo + (Q << 32)
//
// But in this particular case here, the full p_lo is not required.
// Effectively we only need to add the highest bit in p_lo to p_hi (and
// Q_hi + 1 does not overflow).
Q += uint64_t{1} << (64 - 32 - 1); // round, ties up
const uint64_t h = p3 + p2_hi + p1_hi + (Q >> 32);
return {h, x.e + y.e + 64};
}
/*!
@brief normalize x such that the significand is >= 2^(q-1)
@pre x.f != 0
*/
static diyfp normalize(diyfp x) noexcept
{
assert(x.f != 0);
while ((x.f >> 63) == 0)
{
x.f <<= 1;
x.e--;
}
return x;
}
/*!
@brief normalize x such that the result has the exponent E
@pre e >= x.e and the upper e – x.e bits of x.f must be zero.
*/
static diyfp normalize_to(const diyfp& x, const int target_exponent) noexcept
{
const int delta = x.e – target_exponent;
assert(delta >= 0);
assert(((x.f << delta) >> delta) == x.f);
return {x.f << delta, target_exponent};
}
};
struct boundaries
{
diyfp w;
diyfp minus;
diyfp plus;
};
/*!
Compute the (normalized) diyfp representing the input number 'value' and its
boundaries.
@pre value must be finite and positive
*/
template
boundaries compute_boundaries(FloatType value)
{
assert(std::isfinite(value));
assert(value > 0);
// Convert the IEEE representation into a diyfp.
//
// If v is denormal:
// value = 0.F * 2^(1 – bias) = ( F) * 2^(1 – bias – (p-1))
// If v is normalized:
// value = 1.F * 2^(E – bias) = (2^(p-1) + F) * 2^(E – bias – (p-1))
static_assert(std::numeric_limits::is_iec559,
“internal error: dtoa_short requires an IEEE-754 floating-point implementation”);
constexpr int kPrecision = std::numeric_limits::digits; // = p (includes the hidden bit)
constexpr int kBias = std::numeric_limits::max_exponent – 1 + (kPrecision – 1);
constexpr int kMinExp = 1 – kBias;
constexpr uint64_t kHiddenBit = uint64_t{1} << (kPrecision - 1); // = 2^(p-1)
using bits_type = typename std::conditional< kPrecision == 24, uint32_t, uint64_t >::type;
const uint64_t bits = reinterpret_bits(value);
const uint64_t E = bits >> (kPrecision – 1);
const uint64_t F = bits & (kHiddenBit – 1);
const bool is_denormal = (E == 0);
const diyfp v = is_denormal
? diyfp(F, kMinExp)
: diyfp(F + kHiddenBit, static_cast(E) – kBias);
// Compute the boundaries m- and m+ of the floating-point value
// v = f * 2^e.
//
// Determine v- and v+, the floating-point predecessor and successor if v,
// respectively.
//
// v- = v – 2^e if f != 2^(p-1) or e == e_min (A)
// = v – 2^(e-1) if f == 2^(p-1) and e > e_min (B)
//
// v+ = v + 2^e
//
// Let m- = (v- + v) / 2 and m+ = (v + v+) / 2. All real numbers _strictly_
// between m- and m+ round to v, regardless of how the input rounding
// algorithm breaks ties.
//
// —+————-+————-+————-+————-+— (A)
// v- m- v m+ v+
//
// —————–+——+——+————-+————-+— (B)
// v- m- v m+ v+
const bool lower_boundary_is_closer = (F == 0 and E > 1);
const diyfp m_plus = diyfp(2 * v.f + 1, v.e – 1);
const diyfp m_minus = lower_boundary_is_closer
? diyfp(4 * v.f – 1, v.e – 2) // (B)
: diyfp(2 * v.f – 1, v.e – 1); // (A)
// Determine the normalized w+ = m+.
const diyfp w_plus = diyfp::normalize(m_plus);
// Determine w- = m- such that e_(w-) = e_(w+).
const diyfp w_minus = diyfp::normalize_to(m_minus, w_plus.e);
return {diyfp::normalize(v), w_minus, w_plus};
}
// Given normalized diyfp w, Grisu needs to find a (normalized) cached
// power-of-ten c, such that the exponent of the product c * w = f * 2^e lies
// within a certain range [alpha, gamma] (Definition 3.2 from [1])
//
// alpha <= e = e_c + e_w + q <= gamma
//
// or
//
// f_c * f_w * 2^alpha <= f_c 2^(e_c) * f_w 2^(e_w) * 2^q
// <= f_c * f_w * 2^gamma
//
// Since c and w are normalized, i.e. 2^(q-1) <= f < 2^q, this implies
//
// 2^(q-1) * 2^(q-1) * 2^alpha <= c * w * 2^q < 2^q * 2^q * 2^gamma
//
// or
//
// 2^(q - 2 + alpha) <= c * w < 2^(q + gamma)
//
// The choice of (alpha,gamma) determines the size of the table and the form of
// the digit generation procedure. Using (alpha,gamma)=(-60,-32) works out well
// in practice:
//
// The idea is to cut the number c * w = f * 2^e into two parts, which can be
// processed independently: An integral part p1, and a fractional part p2:
//
// f * 2^e = ( (f div 2^-e) * 2^-e + (f mod 2^-e) ) * 2^e
// = (f div 2^-e) + (f mod 2^-e) * 2^e
// = p1 + p2 * 2^e
//
// The conversion of p1 into decimal form requires a series of divisions and
// modulos by (a power of) 10. These operations are faster for 32-bit than for
// 64-bit integers, so p1 should ideally fit into a 32-bit integer. This can be
// achieved by choosing
//
// -e >= 32 or e <= -32 := gamma
//
// In order to convert the fractional part
//
// p2 * 2^e = p2 / 2^-e = d[-1] / 10^1 + d[-2] / 10^2 + ...
//
// into decimal form, the fraction is repeatedly multiplied by 10 and the digits
// d[-i] are extracted in order:
//
// (10 * p2) div 2^-e = d[-1]
// (10 * p2) mod 2^-e = d[-2] / 10^1 + ...
//
// The multiplication by 10 must not overflow. It is sufficient to choose
//
// 10 * p2 < 16 * p2 = 2^4 * p2 <= 2^64.
//
// Since p2 = f mod 2^-e < 2^-e,
//
// -e <= 60 or e >= -60 := alpha
constexpr int kAlpha = -60;
constexpr int kGamma = -32;
struct cached_power // c = f * 2^e ~= 10^k
{
uint64_t f;
int e;
int k;
};
/*!
For a normalized diyfp w = f * 2^e, this function returns a (normalized) cached
power-of-ten c = f_c * 2^e_c, such that the exponent of the product w * c
satisfies (Definition 3.2 from [1])
alpha <= e_c + e + q <= gamma.
*/
inline cached_power get_cached_power_for_binary_exponent(int e)
{
// Now
//
// alpha <= e_c + e + q <= gamma (1)
// ==> f_c * 2^alpha <= c * 2^e * 2^q
//
// and since the c's are normalized, 2^(q-1) <= f_c,
//
// ==> 2^(q – 1 + alpha) <= c * 2^(e + q)
// ==> 2^(alpha – e – 1) <= c
//
// If c were an exakt power of ten, i.e. c = 10^k, one may determine k as
//
// k = ceil( log_10( 2^(alpha - e - 1) ) )
// = ceil( (alpha - e - 1) * log_10(2) )
//
// From the paper:
// "In theory the result of the procedure could be wrong since c is rounded,
// and the computation itself is approximated [...]. In practice, however,
// this simple function is sufficient."
//
// For IEEE double precision floating-point numbers converted into
// normalized diyfp's w = f * 2^e, with q = 64,
//
// e >= -1022 (min IEEE exponent)
// -52 (p – 1)
// -52 (p – 1, possibly normalize denormal IEEE numbers)
// -11 (normalize the diyfp)
// = -1137
//
// and
//
// e <= +1023 (max IEEE exponent)
// -52 (p - 1)
// -11 (normalize the diyfp)
// = 960
//
// This binary exponent range [-1137,960] results in a decimal exponent
// range [-307,324]. One does not need to store a cached power for each
// k in this range. For each such k it suffices to find a cached power
// such that the exponent of the product lies in [alpha,gamma].
// This implies that the difference of the decimal exponents of adjacent
// table entries must be less than or equal to
//
// floor( (gamma - alpha) * log_10(2) ) = 8.
//
// (A smaller distance gamma-alpha would require a larger table.)
// NB:
// Actually this function returns c, such that -60 <= e_c + e + 64 <= -34.
constexpr int kCachedPowersSize = 79;
constexpr int kCachedPowersMinDecExp = -300;
constexpr int kCachedPowersDecStep = 8;
static constexpr cached_power kCachedPowers[] =
{
{ 0xAB70FE17C79AC6CA, -1060, -300 },
{ 0xFF77B1FCBEBCDC4F, -1034, -292 },
{ 0xBE5691EF416BD60C, -1007, -284 },
{ 0x8DD01FAD907FFC3C, -980, -276 },
{ 0xD3515C2831559A83, -954, -268 },
{ 0x9D71AC8FADA6C9B5, -927, -260 },
{ 0xEA9C227723EE8BCB, -901, -252 },
{ 0xAECC49914078536D, -874, -244 },
{ 0x823C12795DB6CE57, -847, -236 },
{ 0xC21094364DFB5637, -821, -228 },
{ 0x9096EA6F3848984F, -794, -220 },
{ 0xD77485CB25823AC7, -768, -212 },
{ 0xA086CFCD97BF97F4, -741, -204 },
{ 0xEF340A98172AACE5, -715, -196 },
{ 0xB23867FB2A35B28E, -688, -188 },
{ 0x84C8D4DFD2C63F3B, -661, -180 },
{ 0xC5DD44271AD3CDBA, -635, -172 },
{ 0x936B9FCEBB25C996, -608, -164 },
{ 0xDBAC6C247D62A584, -582, -156 },
{ 0xA3AB66580D5FDAF6, -555, -148 },
{ 0xF3E2F893DEC3F126, -529, -140 },
{ 0xB5B5ADA8AAFF80B8, -502, -132 },
{ 0x87625F056C7C4A8B, -475, -124 },
{ 0xC9BCFF6034C13053, -449, -116 },
{ 0x964E858C91BA2655, -422, -108 },
{ 0xDFF9772470297EBD, -396, -100 },
{ 0xA6DFBD9FB8E5B88F, -369, -92 },
{ 0xF8A95FCF88747D94, -343, -84 },
{ 0xB94470938FA89BCF, -316, -76 },
{ 0x8A08F0F8BF0F156B, -289, -68 },
{ 0xCDB02555653131B6, -263, -60 },
{ 0x993FE2C6D07B7FAC, -236, -52 },
{ 0xE45C10C42A2B3B06, -210, -44 },
{ 0xAA242499697392D3, -183, -36 },
{ 0xFD87B5F28300CA0E, -157, -28 },
{ 0xBCE5086492111AEB, -130, -20 },
{ 0x8CBCCC096F5088CC, -103, -12 },
{ 0xD1B71758E219652C, -77, -4 },
{ 0x9C40000000000000, -50, 4 },
{ 0xE8D4A51000000000, -24, 12 },
{ 0xAD78EBC5AC620000, 3, 20 },
{ 0x813F3978F8940984, 30, 28 },
{ 0xC097CE7BC90715B3, 56, 36 },
{ 0x8F7E32CE7BEA5C70, 83, 44 },
{ 0xD5D238A4ABE98068, 109, 52 },
{ 0x9F4F2726179A2245, 136, 60 },
{ 0xED63A231D4C4FB27, 162, 68 },
{ 0xB0DE65388CC8ADA8, 189, 76 },
{ 0x83C7088E1AAB65DB, 216, 84 },
{ 0xC45D1DF942711D9A, 242, 92 },
{ 0x924D692CA61BE758, 269, 100 },
{ 0xDA01EE641A708DEA, 295, 108 },
{ 0xA26DA3999AEF774A, 322, 116 },
{ 0xF209787BB47D6B85, 348, 124 },
{ 0xB454E4A179DD1877, 375, 132 },
{ 0x865B86925B9BC5C2, 402, 140 },
{ 0xC83553C5C8965D3D, 428, 148 },
{ 0x952AB45CFA97A0B3, 455, 156 },
{ 0xDE469FBD99A05FE3, 481, 164 },
{ 0xA59BC234DB398C25, 508, 172 },
{ 0xF6C69A72A3989F5C, 534, 180 },
{ 0xB7DCBF5354E9BECE, 561, 188 },
{ 0x88FCF317F22241E2, 588, 196 },
{ 0xCC20CE9BD35C78A5, 614, 204 },
{ 0x98165AF37B2153DF, 641, 212 },
{ 0xE2A0B5DC971F303A, 667, 220 },
{ 0xA8D9D1535CE3B396, 694, 228 },
{ 0xFB9B7CD9A4A7443C, 720, 236 },
{ 0xBB764C4CA7A44410, 747, 244 },
{ 0x8BAB8EEFB6409C1A, 774, 252 },
{ 0xD01FEF10A657842C, 800, 260 },
{ 0x9B10A4E5E9913129, 827, 268 },
{ 0xE7109BFBA19C0C9D, 853, 276 },
{ 0xAC2820D9623BF429, 880, 284 },
{ 0x80444B5E7AA7CF85, 907, 292 },
{ 0xBF21E44003ACDD2D, 933, 300 },
{ 0x8E679C2F5E44FF8F, 960, 308 },
{ 0xD433179D9C8CB841, 986, 316 },
{ 0x9E19DB92B4E31BA9, 1013, 324 },
};
// This computation gives exactly the same results for k as
// k = ceil((kAlpha - e - 1) * 0.30102999566398114)
// for |e| <= 1500, but doesn't require floating-point operations.
// NB: log_10(2) ~= 78913 / 2^18
assert(e >= -1500);
assert(e <= 1500);
const int f = kAlpha - e - 1;
const int k = (f * 78913) / (1 << 18) + static_cast(f > 0);
const int index = (-kCachedPowersMinDecExp + k + (kCachedPowersDecStep – 1)) / kCachedPowersDecStep;
assert(index >= 0);
assert(index < kCachedPowersSize);
static_cast(kCachedPowersSize); // Fix warning.
const cached_power cached = kCachedPowers[index];
assert(kAlpha <= cached.e + e + 64);
assert(kGamma >= cached.e + e + 64);
return cached;
}
/*!
For n != 0, returns k, such that pow10 := 10^(k-1) <= n < 10^k.
For n == 0, returns 1 and sets pow10 := 1.
*/
inline int find_largest_pow10(const uint32_t n, uint32_t& pow10)
{
// LCOV_EXCL_START
if (n >= 1000000000)
{
pow10 = 1000000000;
return 10;
}
// LCOV_EXCL_STOP
else if (n >= 100000000)
{
pow10 = 100000000;
return 9;
}
else if (n >= 10000000)
{
pow10 = 10000000;
return 8;
}
else if (n >= 1000000)
{
pow10 = 1000000;
return 7;
}
else if (n >= 100000)
{
pow10 = 100000;
return 6;
}
else if (n >= 10000)
{
pow10 = 10000;
return 5;
}
else if (n >= 1000)
{
pow10 = 1000;
return 4;
}
else if (n >= 100)
{
pow10 = 100;
return 3;
}
else if (n >= 10)
{
pow10 = 10;
return 2;
}
else
{
pow10 = 1;
return 1;
}
}
inline void grisu2_round(char* buf, int len, uint64_t dist, uint64_t delta,
uint64_t rest, uint64_t ten_k)
{
assert(len >= 1);
assert(dist <= delta);
assert(rest <= delta);
assert(ten_k > 0);
// <--------------------------- delta ---->
// <---- dist --------->
// ————–[——————+——————-]————–
// M- w M+
//
// ten_k
// <------>
// <---- rest ---->
// ————–[——————+—-+————–]————–
// w V
// = buf * 10^k
//
// ten_k represents a unit-in-the-last-place in the decimal representation
// stored in buf.
// Decrement buf by ten_k while this takes buf closer to w.
// The tests are written in this order to avoid overflow in unsigned
// integer arithmetic.
while (rest < dist
and delta - rest >= ten_k
and (rest + ten_k < dist or dist - rest > rest + ten_k – dist))
{
assert(buf[len – 1] != ‘0’);
buf[len – 1]–;
rest += ten_k;
}
}
/*!
Generates V = buffer * 10^decimal_exponent, such that M- <= V <= M+.
M- and M+ must be normalized and share the same exponent -60 <= e <= -32.
*/
inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent,
diyfp M_minus, diyfp w, diyfp M_plus)
{
static_assert(kAlpha >= -60, “internal error”);
static_assert(kGamma <= -32, "internal error");
// Generates the digits (and the exponent) of a decimal floating-point
// number V = buffer * 10^decimal_exponent in the range [M-, M+]. The diyfp's
// w, M- and M+ share the same exponent e, which satisfies alpha <= e <= gamma.
//
// <--------------------------- delta ---->
// <---- dist --------->
// ————–[——————+——————-]————–
// M- w M+
//
// Grisu2 generates the digits of M+ from left to right and stops as soon as
// V is in [M-,M+].
assert(M_plus.e >= kAlpha);
assert(M_plus.e <= kGamma);
uint64_t delta = diyfp::sub(M_plus, M_minus).f; // (significand of (M+ - M-), implicit exponent is e)
uint64_t dist = diyfp::sub(M_plus, w ).f; // (significand of (M+ - w ), implicit exponent is e)
// Split M+ = f * 2^e into two parts p1 and p2 (note: e < 0):
//
// M+ = f * 2^e
// = ((f div 2^-e) * 2^-e + (f mod 2^-e)) * 2^e
// = ((p1 ) * 2^-e + (p2 )) * 2^e
// = p1 + p2 * 2^e
const diyfp one(uint64_t{1} << -M_plus.e, M_plus.e);
auto p1 = static_cast(M_plus.f >> -one.e); // p1 = f div 2^-e (Since -e >= 32, p1 fits into a 32-bit int.)
uint64_t p2 = M_plus.f & (one.f – 1); // p2 = f mod 2^-e
// 1)
//
// Generate the digits of the integral part p1 = d[n-1]…d[1]d[0]
assert(p1 > 0);
uint32_t pow10;
const int k = find_largest_pow10(p1, pow10);
// 10^(k-1) <= p1 < 10^k, pow10 = 10^(k-1)
//
// p1 = (p1 div 10^(k-1)) * 10^(k-1) + (p1 mod 10^(k-1))
// = (d[k-1] ) * 10^(k-1) + (p1 mod 10^(k-1))
//
// M+ = p1 + p2 * 2^e
// = d[k-1] * 10^(k-1) + (p1 mod 10^(k-1)) + p2 * 2^e
// = d[k-1] * 10^(k-1) + ((p1 mod 10^(k-1)) * 2^-e + p2) * 2^e
// = d[k-1] * 10^(k-1) + ( rest) * 2^e
//
// Now generate the digits d[n] of p1 from left to right (n = k-1,...,0)
//
// p1 = d[k-1]...d[n] * 10^n + d[n-1]...d[0]
//
// but stop as soon as
//
// rest * 2^e = (d[n-1]...d[0] * 2^-e + p2) * 2^e <= delta * 2^e
int n = k;
while (n > 0)
{
// Invariants:
// M+ = buffer * 10^n + (p1 + p2 * 2^e) (buffer = 0 for n = k)
// pow10 = 10^(n-1) <= p1 < 10^n
//
const uint32_t d = p1 / pow10; // d = p1 div 10^(n-1)
const uint32_t r = p1 % pow10; // r = p1 mod 10^(n-1)
//
// M+ = buffer * 10^n + (d * 10^(n-1) + r) + p2 * 2^e
// = (buffer * 10 + d) * 10^(n-1) + (r + p2 * 2^e)
//
assert(d <= 9);
buffer[length++] = static_cast(‘0’ + d); // buffer := buffer * 10 + d
//
// M+ = buffer * 10^(n-1) + (r + p2 * 2^e)
//
p1 = r;
n–;
//
// M+ = buffer * 10^n + (p1 + p2 * 2^e)
// pow10 = 10^n
//
// Now check if enough digits have been generated.
// Compute
//
// p1 + p2 * 2^e = (p1 * 2^-e + p2) * 2^e = rest * 2^e
//
// Note:
// Since rest and delta share the same exponent e, it suffices to
// compare the significands.
const uint64_t rest = (uint64_t{p1} << -one.e) + p2;
if (rest <= delta)
{
// V = buffer * 10^n, with M- <= V <= M+.
decimal_exponent += n;
// We may now just stop. But instead look if the buffer could be
// decremented to bring V closer to w.
//
// pow10 = 10^n is now 1 ulp in the decimal representation V.
// The rounding procedure works with diyfp's with an implicit
// exponent of e.
//
// 10^n = (10^n * 2^-e) * 2^e = ulp * 2^e
//
const uint64_t ten_n = uint64_t{pow10} << -one.e;
grisu2_round(buffer, length, dist, delta, rest, ten_n);
return;
}
pow10 /= 10;
//
// pow10 = 10^(n-1) <= p1 < 10^n
// Invariants restored.
}
// 2)
//
// The digits of the integral part have been generated:
//
// M+ = d[k-1]...d[1]d[0] + p2 * 2^e
// = buffer + p2 * 2^e
//
// Now generate the digits of the fractional part p2 * 2^e.
//
// Note:
// No decimal point is generated: the exponent is adjusted instead.
//
// p2 actually represents the fraction
//
// p2 * 2^e
// = p2 / 2^-e
// = d[-1] / 10^1 + d[-2] / 10^2 + ...
//
// Now generate the digits d[-m] of p1 from left to right (m = 1,2,...)
//
// p2 * 2^e = d[-1]d[-2]...d[-m] * 10^-m
// + 10^-m * (d[-m-1] / 10^1 + d[-m-2] / 10^2 + ...)
//
// using
//
// 10^m * p2 = ((10^m * p2) div 2^-e) * 2^-e + ((10^m * p2) mod 2^-e)
// = ( d) * 2^-e + ( r)
//
// or
// 10^m * p2 * 2^e = d + r * 2^e
//
// i.e.
//
// M+ = buffer + p2 * 2^e
// = buffer + 10^-m * (d + r * 2^e)
// = (buffer * 10^m + d) * 10^-m + 10^-m * r * 2^e
//
// and stop as soon as 10^-m * r * 2^e <= delta * 2^e
assert(p2 > delta);
int m = 0;
for (;;)
{
// Invariant:
// M+ = buffer * 10^-m + 10^-m * (d[-m-1] / 10 + d[-m-2] / 10^2 + …) * 2^e
// = buffer * 10^-m + 10^-m * (p2 ) * 2^e
// = buffer * 10^-m + 10^-m * (1/10 * (10 * p2) ) * 2^e
// = buffer * 10^-m + 10^-m * (1/10 * ((10*p2 div 2^-e) * 2^-e + (10*p2 mod 2^-e)) * 2^e
//
assert(p2 <= UINT64_MAX / 10);
p2 *= 10;
const uint64_t d = p2 >> -one.e; // d = (10 * p2) div 2^-e
const uint64_t r = p2 & (one.f – 1); // r = (10 * p2) mod 2^-e
//
// M+ = buffer * 10^-m + 10^-m * (1/10 * (d * 2^-e + r) * 2^e
// = buffer * 10^-m + 10^-m * (1/10 * (d + r * 2^e))
// = (buffer * 10 + d) * 10^(-m-1) + 10^(-m-1) * r * 2^e
//
assert(d <= 9);
buffer[length++] = static_cast(‘0’ + d); // buffer := buffer * 10 + d
//
// M+ = buffer * 10^(-m-1) + 10^(-m-1) * r * 2^e
//
p2 = r;
m++;
//
// M+ = buffer * 10^-m + 10^-m * p2 * 2^e
// Invariant restored.
// Check if enough digits have been generated.
//
// 10^-m * p2 * 2^e <= delta * 2^e
// p2 * 2^e <= 10^m * delta * 2^e
// p2 <= 10^m * delta
delta *= 10;
dist *= 10;
if (p2 <= delta)
{
break;
}
}
// V = buffer * 10^-m, with M- <= V <= M+.
decimal_exponent -= m;
// 1 ulp in the decimal representation is now 10^-m.
// Since delta and dist are now scaled by 10^m, we need to do the
// same with ulp in order to keep the units in sync.
//
// 10^m * 10^-m = 1 = 2^-e * 2^e = ten_m * 2^e
//
const uint64_t ten_m = one.f;
grisu2_round(buffer, length, dist, delta, p2, ten_m);
// By construction this algorithm generates the shortest possible decimal
// number (Loitsch, Theorem 6.2) which rounds back to w.
// For an input number of precision p, at least
//
// N = 1 + ceil(p * log_10(2))
//
// decimal digits are sufficient to identify all binary floating-point
// numbers (Matula, "In-and-Out conversions").
// This implies that the algorithm does not produce more than N decimal
// digits.
//
// N = 17 for p = 53 (IEEE double precision)
// N = 9 for p = 24 (IEEE single precision)
}
/*!
v = buf * 10^decimal_exponent
len is the length of the buffer (number of decimal digits)
The buffer must be large enough, i.e. >= max_digits10.
*/
inline void grisu2(char* buf, int& len, int& decimal_exponent,
diyfp m_minus, diyfp v, diyfp m_plus)
{
assert(m_plus.e == m_minus.e);
assert(m_plus.e == v.e);
// ——–(———————–+———————–)——– (A)
// m- v m+
//
// ——————–(———–+———————–)——– (B)
// m- v m+
//
// First scale v (and m- and m+) such that the exponent is in the range
// [alpha, gamma].
const cached_power cached = get_cached_power_for_binary_exponent(m_plus.e);
const diyfp c_minus_k(cached.f, cached.e); // = c ~= 10^-k
// The exponent of the products is = v.e + c_minus_k.e + q and is in the range [alpha,gamma]
const diyfp w = diyfp::mul(v, c_minus_k);
const diyfp w_minus = diyfp::mul(m_minus, c_minus_k);
const diyfp w_plus = diyfp::mul(m_plus, c_minus_k);
// —-(—+—)—————(—+—)—————(—+—)—-
// w- w w+
// = c*m- = c*v = c*m+
//
// diyfp::mul rounds its result and c_minus_k is approximated too. w, w- and
// w+ are now off by a small amount.
// In fact:
//
// w – v * 10^k < 1 ulp
//
// To account for this inaccuracy, add resp. subtract 1 ulp.
//
// --------+---[---------------(---+---)---------------]---+--------
// w- M- w M+ w+
//
// Now any number in [M-, M+] (bounds included) will round to w when input,
// regardless of how the input rounding algorithm breaks ties.
//
// And digit_gen generates the shortest possible such number in [M-, M+].
// Note that this does not mean that Grisu2 always generates the shortest
// possible number in the interval (m-, m+).
const diyfp M_minus(w_minus.f + 1, w_minus.e);
const diyfp M_plus (w_plus.f - 1, w_plus.e );
decimal_exponent = -cached.k; // = -(-k) = k
grisu2_digit_gen(buf, len, decimal_exponent, M_minus, w, M_plus);
}
/*!
v = buf * 10^decimal_exponent
len is the length of the buffer (number of decimal digits)
The buffer must be large enough, i.e. >= max_digits10.
*/
template
void grisu2(char* buf, int& len, int& decimal_exponent, FloatType value)
{
static_assert(diyfp::kPrecision >= std::numeric_limits::digits + 3,
“internal error: not enough precision”);
assert(std::isfinite(value));
assert(value > 0);
// If the neighbors (and boundaries) of ‘value’ are always computed for double-precision
// numbers, all float’s can be recovered using strtod (and strtof). However, the resulting
// decimal representations are not exactly “short”.
//
// The documentation for ‘std::to_chars’ (https://en.cppreference.com/w/cpp/utility/to_chars)
// says “value is converted to a string as if by std::sprintf in the default (“C”) locale”
// and since sprintf promotes float’s to double’s, I think this is exactly what ‘std::to_chars’
// does.
// On the other hand, the documentation for ‘std::to_chars’ requires that “parsing the
// representation using the corresponding std::from_chars function recovers value exactly”. That
// indicates that single precision floating-point numbers should be recovered using
// ‘std::strtof’.
//
// NB: If the neighbors are computed for single-precision numbers, there is a single float
// (7.0385307e-26f) which can’t be recovered using strtod. The resulting double precision
// value is off by 1 ulp.
#if 0
const boundaries w = compute_boundaries(static_cast(value));
#else
const boundaries w = compute_boundaries(value);
#endif
grisu2(buf, len, decimal_exponent, w.minus, w.w, w.plus);
}
/*!
@brief appends a decimal representation of e to buf
@return a pointer to the element following the exponent.
@pre -1000 < e < 1000
*/
inline char* append_exponent(char* buf, int e)
{
assert(e > -1000);
assert(e < 1000);
if (e < 0)
{
e = -e;
*buf++ = '-';
}
else
{
*buf++ = '+';
}
auto k = static_cast(e);
if (k < 10)
{
// Always print at least two digits in the exponent.
// This is for compatibility with printf("%g").
*buf++ = '0';
*buf++ = static_cast(‘0’ + k);
}
else if (k < 100)
{
*buf++ = static_cast(‘0’ + k / 10);
k %= 10;
*buf++ = static_cast(‘0’ + k);
}
else
{
*buf++ = static_cast(‘0’ + k / 100);
k %= 100;
*buf++ = static_cast(‘0’ + k / 10);
k %= 10;
*buf++ = static_cast(‘0’ + k);
}
return buf;
}
/*!
@brief prettify v = buf * 10^decimal_exponent
If v is in the range [10^min_exp, 10^max_exp) it will be printed in fixed-point
notation. Otherwise it will be printed in exponential notation.
@pre min_exp < 0
@pre max_exp > 0
*/
inline char* format_buffer(char* buf, int len, int decimal_exponent,
int min_exp, int max_exp)
{
assert(min_exp < 0);
assert(max_exp > 0);
const int k = len;
const int n = len + decimal_exponent;
// v = buf * 10^(n-k)
// k is the length of the buffer (number of decimal digits)
// n is the position of the decimal point relative to the start of the buffer.
if (k <= n and n <= max_exp)
{
// digits[000]
// len <= max_exp + 2
std::memset(buf + k, '0', static_cast(n – k));
// Make it look like a floating-point number (#362, #378)
buf[n + 0] = ‘.’;
buf[n + 1] = ‘0’;
return buf + (n + 2);
}
if (0 < n and n <= max_exp)
{
// dig.its
// len <= max_digits10 + 1
assert(k > n);
std::memmove(buf + (n + 1), buf + n, static_cast(k – n));
buf[n] = ‘.’;
return buf + (k + 1);
}
if (min_exp < n and n <= 0)
{
// 0.[000]digits
// len <= 2 + (-min_exp - 1) + max_digits10
std::memmove(buf + (2 + -n), buf, static_cast(k));
buf[0] = ‘0’;
buf[1] = ‘.’;
std::memset(buf + 2, ‘0’, static_cast(-n));
return buf + (2 + (-n) + k);
}
if (k == 1)
{
// dE+123
// len <= 1 + 5
buf += 1;
}
else
{
// d.igitsE+123
// len <= max_digits10 + 1 + 5
std::memmove(buf + 2, buf + 1, static_cast(k – 1));
buf[1] = ‘.’;
buf += 1 + k;
}
*buf++ = ‘e’;
return append_exponent(buf, n – 1);
}
} // namespace dtoa_impl
/*!
@brief generates a decimal representation of the floating-point number value in [first, last).
The format of the resulting decimal representation is similar to printf’s %g
format. Returns an iterator pointing past-the-end of the decimal representation.
@note The input number must be finite, i.e. NaN’s and Inf’s are not supported.
@note The buffer must be large enough.
@note The result is NOT null-terminated.
*/
template
char* to_chars(char* first, const char* last, FloatType value)
{
static_cast(last); // maybe unused – fix warning
assert(std::isfinite(value));
// Use signbit(value) instead of (value < 0) since signbit works for -0.
if (std::signbit(value))
{
value = -value;
*first++ = '-';
}
if (value == 0) // +-0
{
*first++ = '0';
// Make it look like a floating-point number (#362, #378)
*first++ = '.';
*first++ = '0';
return first;
}
assert(last - first >= std::numeric_limits::max_digits10);
// Compute v = buffer * 10^decimal_exponent.
// The decimal digits are stored in the buffer, which needs to be interpreted
// as an unsigned decimal integer.
// len is the length of the buffer, i.e. the number of decimal digits.
int len = 0;
int decimal_exponent = 0;
dtoa_impl::grisu2(first, len, decimal_exponent, value);
assert(len <= std::numeric_limits::max_digits10);
// Format the buffer like printf(“%.*g”, prec, value)
constexpr int kMinExp = -4;
// Use digits10 here to increase compatibility with version 2.
constexpr int kMaxExp = std::numeric_limits::digits10;
assert(last – first >= kMaxExp + 2);
assert(last – first >= 2 + (-kMinExp – 1) + std::numeric_limits::max_digits10);
assert(last – first >= std::numeric_limits::max_digits10 + 6);
return dtoa_impl::format_buffer(first, len, decimal_exponent, kMinExp, kMaxExp);
}
} // namespace detail
} // namespace nlohmann
// #include
// #include
// #include
// #include
// #include
namespace nlohmann
{
namespace detail
{
///////////////////
// serialization //
///////////////////
/// how to treat decoding errors
enum class error_handler_t
{
strict, ///< throw a type_error exception in case of invalid UTF-8
replace, ///< replace invalid UTF-8 sequences with U+FFFD
ignore ///< ignore invalid UTF-8 sequences
};
template
class serializer
{
using string_t = typename BasicJsonType::string_t;
using number_float_t = typename BasicJsonType::number_float_t;
using number_integer_t = typename BasicJsonType::number_integer_t;
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
static constexpr uint8_t UTF8_ACCEPT = 0;
static constexpr uint8_t UTF8_REJECT = 1;
public:
/*!
@param[in] s output stream to serialize to
@param[in] ichar indentation character to use
@param[in] error_handler_ how to react on decoding errors
*/
serializer(output_adapter_t s, const char ichar,
error_handler_t error_handler_ = error_handler_t::strict)
: o(std::move(s))
, loc(std::localeconv())
, thousands_sep(loc->thousands_sep == nullptr ? ‘\0’ : * (loc->thousands_sep))
, decimal_point(loc->decimal_point == nullptr ? ‘\0’ : * (loc->decimal_point))
, indent_char(ichar)
, indent_string(512, indent_char)
, error_handler(error_handler_)
{}
// delete because of pointer members
serializer(const serializer&) = delete;
serializer& operator=(const serializer&) = delete;
serializer(serializer&&) = delete;
serializer& operator=(serializer&&) = delete;
~serializer() = default;
/*!
@brief internal implementation of the serialization function
This function is called by the public member function dump and organizes
the serialization internally. The indentation level is propagated as
additional parameter. In case of arrays and objects, the function is
called recursively.
– strings and object keys are escaped using `escape_string()`
– integer numbers are converted implicitly via `operator<<`
- floating-point numbers are converted to a string using `"%g"` format
@param[in] val value to serialize
@param[in] pretty_print whether the output shall be pretty-printed
@param[in] indent_step the indent level
@param[in] current_indent the current indent level (only used internally)
*/
void dump(const BasicJsonType& val, const bool pretty_print,
const bool ensure_ascii,
const unsigned int indent_step,
const unsigned int current_indent = 0)
{
switch (val.m_type)
{
case value_t::object:
{
if (val.m_value.object->empty())
{
o->write_characters(“{}”, 2);
return;
}
if (pretty_print)
{
o->write_characters(“{\n”, 2);
// variable to hold indentation for recursive calls
const auto new_indent = current_indent + indent_step;
if (JSON_UNLIKELY(indent_string.size() < new_indent))
{
indent_string.resize(indent_string.size() * 2, ' ');
}
// first n-1 elements
auto i = val.m_value.object->cbegin();
for (std::size_t cnt = 0; cnt < val.m_value.object->size() – 1; ++cnt, ++i)
{
o->write_characters(indent_string.c_str(), new_indent);
o->write_character(‘\”‘);
dump_escaped(i->first, ensure_ascii);
o->write_characters(“\”: “, 3);
dump(i->second, true, ensure_ascii, indent_step, new_indent);
o->write_characters(“,\n”, 2);
}
// last element
assert(i != val.m_value.object->cend());
assert(std::next(i) == val.m_value.object->cend());
o->write_characters(indent_string.c_str(), new_indent);
o->write_character(‘\”‘);
dump_escaped(i->first, ensure_ascii);
o->write_characters(“\”: “, 3);
dump(i->second, true, ensure_ascii, indent_step, new_indent);
o->write_character(‘\n’);
o->write_characters(indent_string.c_str(), current_indent);
o->write_character(‘}’);
}
else
{
o->write_character(‘{‘);
// first n-1 elements
auto i = val.m_value.object->cbegin();
for (std::size_t cnt = 0; cnt < val.m_value.object->size() – 1; ++cnt, ++i)
{
o->write_character(‘\”‘);
dump_escaped(i->first, ensure_ascii);
o->write_characters(“\”:”, 2);
dump(i->second, false, ensure_ascii, indent_step, current_indent);
o->write_character(‘,’);
}
// last element
assert(i != val.m_value.object->cend());
assert(std::next(i) == val.m_value.object->cend());
o->write_character(‘\”‘);
dump_escaped(i->first, ensure_ascii);
o->write_characters(“\”:”, 2);
dump(i->second, false, ensure_ascii, indent_step, current_indent);
o->write_character(‘}’);
}
return;
}
case value_t::array:
{
if (val.m_value.array->empty())
{
o->write_characters(“[]”, 2);
return;
}
if (pretty_print)
{
o->write_characters(“[\n”, 2);
// variable to hold indentation for recursive calls
const auto new_indent = current_indent + indent_step;
if (JSON_UNLIKELY(indent_string.size() < new_indent))
{
indent_string.resize(indent_string.size() * 2, ' ');
}
// first n-1 elements
for (auto i = val.m_value.array->cbegin();
i != val.m_value.array->cend() – 1; ++i)
{
o->write_characters(indent_string.c_str(), new_indent);
dump(*i, true, ensure_ascii, indent_step, new_indent);
o->write_characters(“,\n”, 2);
}
// last element
assert(not val.m_value.array->empty());
o->write_characters(indent_string.c_str(), new_indent);
dump(val.m_value.array->back(), true, ensure_ascii, indent_step, new_indent);
o->write_character(‘\n’);
o->write_characters(indent_string.c_str(), current_indent);
o->write_character(‘]’);
}
else
{
o->write_character(‘[‘);
// first n-1 elements
for (auto i = val.m_value.array->cbegin();
i != val.m_value.array->cend() – 1; ++i)
{
dump(*i, false, ensure_ascii, indent_step, current_indent);
o->write_character(‘,’);
}
// last element
assert(not val.m_value.array->empty());
dump(val.m_value.array->back(), false, ensure_ascii, indent_step, current_indent);
o->write_character(‘]’);
}
return;
}
case value_t::string:
{
o->write_character(‘\”‘);
dump_escaped(*val.m_value.string, ensure_ascii);
o->write_character(‘\”‘);
return;
}
case value_t::boolean:
{
if (val.m_value.boolean)
{
o->write_characters(“true”, 4);
}
else
{
o->write_characters(“false”, 5);
}
return;
}
case value_t::number_integer:
{
dump_integer(val.m_value.number_integer);
return;
}
case value_t::number_unsigned:
{
dump_integer(val.m_value.number_unsigned);
return;
}
case value_t::number_float:
{
dump_float(val.m_value.number_float);
return;
}
case value_t::discarded:
{
o->write_characters(““, 11);
return;
}
case value_t::null:
{
o->write_characters(“null”, 4);
return;
}
}
}
private:
/*!
@brief dump escaped string
Escape a string by replacing certain special characters by a sequence of an
escape character (backslash) and another character and other control
characters by a sequence of “\u” followed by a four-digit hex
representation. The escaped string is written to output stream @a o.
@param[in] s the string to escape
@param[in] ensure_ascii whether to escape non-ASCII characters with
\uXXXX sequences
@complexity Linear in the length of string @a s.
*/
void dump_escaped(const string_t& s, const bool ensure_ascii)
{
uint32_t codepoint;
uint8_t state = UTF8_ACCEPT;
std::size_t bytes = 0; // number of bytes written to string_buffer
// number of bytes written at the point of the last valid byte
std::size_t bytes_after_last_accept = 0;
std::size_t undumped_chars = 0;
for (std::size_t i = 0; i < s.size(); ++i)
{
const auto byte = static_cast(s[i]);
switch (decode(state, codepoint, byte))
{
case UTF8_ACCEPT: // decode found a new code point
{
switch (codepoint)
{
case 0x08: // backspace
{
string_buffer[bytes++] = ‘\\’;
string_buffer[bytes++] = ‘b’;
break;
}
case 0x09: // horizontal tab
{
string_buffer[bytes++] = ‘\\’;
string_buffer[bytes++] = ‘t’;
break;
}
case 0x0A: // newline
{
string_buffer[bytes++] = ‘\\’;
string_buffer[bytes++] = ‘n’;
break;
}
case 0x0C: // formfeed
{
string_buffer[bytes++] = ‘\\’;
string_buffer[bytes++] = ‘f’;
break;
}
case 0x0D: // carriage return
{
string_buffer[bytes++] = ‘\\’;
string_buffer[bytes++] = ‘r’;
break;
}
case 0x22: // quotation mark
{
string_buffer[bytes++] = ‘\\’;
string_buffer[bytes++] = ‘\”‘;
break;
}
case 0x5C: // reverse solidus
{
string_buffer[bytes++] = ‘\\’;
string_buffer[bytes++] = ‘\\’;
break;
}
default:
{
// escape control characters (0x00..0x1F) or, if
// ensure_ascii parameter is used, non-ASCII characters
if ((codepoint <= 0x1F) or (ensure_ascii and (codepoint >= 0x7F)))
{
if (codepoint <= 0xFFFF)
{
(std::snprintf)(string_buffer.data() + bytes, 7, "\\u%04x",
static_cast(codepoint));
bytes += 6;
}
else
{
(std::snprintf)(string_buffer.data() + bytes, 13, “\\u%04x\\u%04x”,
static_cast(0xD7C0 + (codepoint >> 10)),
static_cast(0xDC00 + (codepoint & 0x3FF)));
bytes += 12;
}
}
else
{
// copy byte to buffer (all previous bytes
// been copied have in default case above)
string_buffer[bytes++] = s[i];
}
break;
}
}
// write buffer and reset index; there must be 13 bytes
// left, as this is the maximal number of bytes to be
// written (“\uxxxx\uxxxx\0”) for one code point
if (string_buffer.size() – bytes < 13)
{
o->write_characters(string_buffer.data(), bytes);
bytes = 0;
}
// remember the byte position of this accept
bytes_after_last_accept = bytes;
undumped_chars = 0;
break;
}
case UTF8_REJECT: // decode found invalid UTF-8 byte
{
switch (error_handler)
{
case error_handler_t::strict:
{
std::string sn(3, ‘\0’);
(std::snprintf)(&sn[0], sn.size(), “%.2X”, byte);
JSON_THROW(type_error::create(316, “invalid UTF-8 byte at index ” + std::to_string(i) + “: 0x” + sn));
}
case error_handler_t::ignore:
case error_handler_t::replace:
{
// in case we saw this character the first time, we
// would like to read it again, because the byte
// may be OK for itself, but just not OK for the
// previous sequence
if (undumped_chars > 0)
{
–i;
}
// reset length buffer to the last accepted index;
// thus removing/ignoring the invalid characters
bytes = bytes_after_last_accept;
if (error_handler == error_handler_t::replace)
{
// add a replacement character
if (ensure_ascii)
{
string_buffer[bytes++] = ‘\\’;
string_buffer[bytes++] = ‘u’;
string_buffer[bytes++] = ‘f’;
string_buffer[bytes++] = ‘f’;
string_buffer[bytes++] = ‘f’;
string_buffer[bytes++] = ‘d’;
}
else
{
string_buffer[bytes++] = detail::binary_writer::to_char_type(‘\xEF’);
string_buffer[bytes++] = detail::binary_writer::to_char_type(‘\xBF’);
string_buffer[bytes++] = detail::binary_writer::to_char_type(‘\xBD’);
}
// write buffer and reset index; there must be 13 bytes
// left, as this is the maximal number of bytes to be
// written (“\uxxxx\uxxxx\0”) for one code point
if (string_buffer.size() – bytes < 13)
{
o->write_characters(string_buffer.data(), bytes);
bytes = 0;
}
bytes_after_last_accept = bytes;
}
undumped_chars = 0;
// continue processing the string
state = UTF8_ACCEPT;
break;
}
}
break;
}
default: // decode found yet incomplete multi-byte code point
{
if (not ensure_ascii)
{
// code point will not be escaped – copy byte to buffer
string_buffer[bytes++] = s[i];
}
++undumped_chars;
break;
}
}
}
// we finished processing the string
if (JSON_LIKELY(state == UTF8_ACCEPT))
{
// write buffer
if (bytes > 0)
{
o->write_characters(string_buffer.data(), bytes);
}
}
else
{
// we finish reading, but do not accept: string was incomplete
switch (error_handler)
{
case error_handler_t::strict:
{
std::string sn(3, ‘\0’);
(std::snprintf)(&sn[0], sn.size(), “%.2X”, static_cast(s.back()));
JSON_THROW(type_error::create(316, “incomplete UTF-8 string; last byte: 0x” + sn));
}
case error_handler_t::ignore:
{
// write all accepted bytes
o->write_characters(string_buffer.data(), bytes_after_last_accept);
break;
}
case error_handler_t::replace:
{
// write all accepted bytes
o->write_characters(string_buffer.data(), bytes_after_last_accept);
// add a replacement character
if (ensure_ascii)
{
o->write_characters(“\\ufffd”, 6);
}
else
{
o->write_characters(“\xEF\xBF\xBD”, 3);
}
break;
}
}
}
}
/*!
@brief count digits
Count the number of decimal (base 10) digits for an input unsigned integer.
@param[in] x unsigned integer number to count its digits
@return number of decimal digits
*/
inline unsigned int count_digits(number_unsigned_t x) noexcept
{
unsigned int n_digits = 1;
for (;;)
{
if (x < 10)
{
return n_digits;
}
if (x < 100)
{
return n_digits + 1;
}
if (x < 1000)
{
return n_digits + 2;
}
if (x < 10000)
{
return n_digits + 3;
}
x = x / 10000u;
n_digits += 4;
}
}
/*!
@brief dump an integer
Dump a given integer to output stream @a o. Works internally with
@a number_buffer.
@param[in] x integer number (signed or unsigned) to dump
@tparam NumberType either @a number_integer_t or @a number_unsigned_t
*/
template::value or
std::is_same::value,
int> = 0>
void dump_integer(NumberType x)
{
static constexpr std::array, 100> digits_to_99
{
{
// EECS280 modification
{{‘0’, ‘0’}}, {{‘0’, ‘1’}}, {{‘0’, ‘2’}}, {{‘0’, ‘3’}}, {{‘0’, ‘4’}}, {{‘0’, ‘5’}}, {{‘0’, ‘6’}}, {{‘0’, ‘7’}}, {{‘0’, ‘8’}}, {{‘0’, ‘9’}},
{{‘1’, ‘0’}}, {{‘1’, ‘1’}}, {{‘1’, ‘2’}}, {{‘1’, ‘3’}}, {{‘1’, ‘4’}}, {{‘1’, ‘5’}}, {{‘1’, ‘6’}}, {{‘1’, ‘7’}}, {{‘1’, ‘8’}}, {{‘1’, ‘9’}},
{{‘2’, ‘0’}}, {{‘2’, ‘1’}}, {{‘2’, ‘2’}}, {{‘2’, ‘3’}}, {{‘2’, ‘4’}}, {{‘2’, ‘5’}}, {{‘2’, ‘6’}}, {{‘2’, ‘7’}}, {{‘2’, ‘8’}}, {{‘2’, ‘9’}},
{{‘3’, ‘0’}}, {{‘3’, ‘1’}}, {{‘3’, ‘2’}}, {{‘3’, ‘3’}}, {{‘3’, ‘4’}}, {{‘3’, ‘5’}}, {{‘3’, ‘6’}}, {{‘3’, ‘7’}}, {{‘3’, ‘8’}}, {{‘3’, ‘9’}},
{{‘4’, ‘0’}}, {{‘4’, ‘1’}}, {{‘4’, ‘2’}}, {{‘4’, ‘3’}}, {{‘4’, ‘4’}}, {{‘4’, ‘5’}}, {{‘4’, ‘6’}}, {{‘4’, ‘7’}}, {{‘4’, ‘8’}}, {{‘4’, ‘9’}},
{{‘5’, ‘0’}}, {{‘5’, ‘1’}}, {{‘5’, ‘2’}}, {{‘5’, ‘3’}}, {{‘5’, ‘4’}}, {{‘5’, ‘5’}}, {{‘5’, ‘6’}}, {{‘5’, ‘7’}}, {{‘5’, ‘8’}}, {{‘5’, ‘9’}},
{{‘6’, ‘0’}}, {{‘6’, ‘1’}}, {{‘6’, ‘2’}}, {{‘6’, ‘3’}}, {{‘6’, ‘4’}}, {{‘6’, ‘5’}}, {{‘6’, ‘6’}}, {{‘6’, ‘7’}}, {{‘6’, ‘8’}}, {{‘6’, ‘9’}},
{{‘7’, ‘0’}}, {{‘7’, ‘1’}}, {{‘7’, ‘2’}}, {{‘7’, ‘3’}}, {{‘7’, ‘4’}}, {{‘7’, ‘5’}}, {{‘7’, ‘6’}}, {{‘7’, ‘7’}}, {{‘7’, ‘8’}}, {{‘7’, ‘9’}},
{{‘8’, ‘0’}}, {{‘8’, ‘1’}}, {{‘8’, ‘2’}}, {{‘8’, ‘3’}}, {{‘8’, ‘4’}}, {{‘8’, ‘5’}}, {{‘8’, ‘6’}}, {{‘8’, ‘7’}}, {{‘8’, ‘8’}}, {{‘8’, ‘9’}},
{{‘9’, ‘0’}}, {{‘9’, ‘1’}}, {{‘9’, ‘2’}}, {{‘9’, ‘3’}}, {{‘9’, ‘4’}}, {{‘9’, ‘5’}}, {{‘9’, ‘6’}}, {{‘9’, ‘7’}}, {{‘9’, ‘8’}}, {{‘9’, ‘9’}},
// ORIGINAL
// {‘0’, ‘0’}, {‘0’, ‘1’}, {‘0’, ‘2’}, {‘0’, ‘3’}, {‘0’, ‘4’}, {‘0’, ‘5’}, {‘0’, ‘6’}, {‘0’, ‘7’}, {‘0’, ‘8’}, {‘0’, ‘9’},
// {‘1’, ‘0’}, {‘1’, ‘1’}, {‘1’, ‘2’}, {‘1’, ‘3’}, {‘1’, ‘4’}, {‘1’, ‘5’}, {‘1’, ‘6’}, {‘1’, ‘7’}, {‘1’, ‘8’}, {‘1’, ‘9’},
// {‘2’, ‘0’}, {‘2’, ‘1’}, {‘2’, ‘2’}, {‘2’, ‘3’}, {‘2’, ‘4’}, {‘2’, ‘5’}, {‘2’, ‘6’}, {‘2’, ‘7’}, {‘2’, ‘8’}, {‘2’, ‘9’},
// {‘3’, ‘0’}, {‘3’, ‘1’}, {‘3’, ‘2’}, {‘3’, ‘3’}, {‘3’, ‘4’}, {‘3’, ‘5’}, {‘3’, ‘6’}, {‘3’, ‘7’}, {‘3’, ‘8’}, {‘3’, ‘9’},
// {‘4’, ‘0’}, {‘4’, ‘1’}, {‘4’, ‘2’}, {‘4’, ‘3’}, {‘4’, ‘4’}, {‘4’, ‘5’}, {‘4’, ‘6’}, {‘4’, ‘7’}, {‘4’, ‘8’}, {‘4’, ‘9’},
// {‘5’, ‘0’}, {‘5’, ‘1’}, {‘5’, ‘2’}, {‘5’, ‘3’}, {‘5’, ‘4’}, {‘5’, ‘5’}, {‘5’, ‘6’}, {‘5’, ‘7’}, {‘5’, ‘8’}, {‘5’, ‘9’},
// {‘6’, ‘0’}, {‘6’, ‘1’}, {‘6’, ‘2’}, {‘6’, ‘3’}, {‘6’, ‘4’}, {‘6’, ‘5’}, {‘6’, ‘6’}, {‘6’, ‘7’}, {‘6’, ‘8’}, {‘6’, ‘9’},
// {‘7’, ‘0’}, {‘7’, ‘1’}, {‘7’, ‘2’}, {‘7’, ‘3’}, {‘7’, ‘4’}, {‘7’, ‘5’}, {‘7’, ‘6’}, {‘7’, ‘7’}, {‘7’, ‘8’}, {‘7’, ‘9’},
// {‘8’, ‘0’}, {‘8’, ‘1’}, {‘8’, ‘2’}, {‘8’, ‘3’}, {‘8’, ‘4’}, {‘8’, ‘5’}, {‘8’, ‘6’}, {‘8’, ‘7’}, {‘8’, ‘8’}, {‘8’, ‘9’},
// {‘9’, ‘0’}, {‘9’, ‘1’}, {‘9’, ‘2’}, {‘9’, ‘3’}, {‘9’, ‘4’}, {‘9’, ‘5’}, {‘9’, ‘6’}, {‘9’, ‘7’}, {‘9’, ‘8’}, {‘9’, ‘9’},
}
};
// special case for “0”
if (x == 0)
{
o->write_character(‘0’);
return;
}
// use a pointer to fill the buffer
auto buffer_ptr = begin(number_buffer);
const bool is_negative = std::is_same::value and not(x >= 0); // see issue #755
number_unsigned_t abs_value;
unsigned int n_chars;
if (is_negative)
{
*buffer_ptr = ‘-‘;
abs_value = static_cast(-1 – x) + 1;
// account one more byte for the minus sign
n_chars = 1 + count_digits(abs_value);
}
else
{
abs_value = static_cast(x);
n_chars = count_digits(abs_value);
}
// spare 1 byte for ‘\0’
assert(n_chars < number_buffer.size() - 1);
// jump to the end to generate the string from backward
// so we later avoid reversing the result
buffer_ptr += n_chars;
// Fast int2ascii implementation inspired by "Fastware" talk by Andrei Alexandrescu
// See: https://www.youtube.com/watch?v=o4-CwDo2zpg
while (abs_value >= 100)
{
const auto digits_index = static_cast((abs_value % 100));
abs_value /= 100;
*(–buffer_ptr) = digits_to_99[digits_index][1];
*(–buffer_ptr) = digits_to_99[digits_index][0];
}
if (abs_value >= 10)
{
const auto digits_index = static_cast(abs_value);
*(–buffer_ptr) = digits_to_99[digits_index][1];
*(–buffer_ptr) = digits_to_99[digits_index][0];
}
else
{
*(–buffer_ptr) = static_cast(‘0’ + abs_value);
}
o->write_characters(number_buffer.data(), n_chars);
}
/*!
@brief dump a floating-point number
Dump a given floating-point number to output stream @a o. Works internally
with @a number_buffer.
@param[in] x floating-point number to dump
*/
void dump_float(number_float_t x)
{
// NaN / inf
if (not std::isfinite(x))
{
o->write_characters(“null”, 4);
return;
}
// If number_float_t is an IEEE-754 single or double precision number,
// use the Grisu2 algorithm to produce short numbers which are
// guaranteed to round-trip, using strtof and strtod, resp.
//
// NB: The test below works if == .
static constexpr bool is_ieee_single_or_double
= (std::numeric_limits::is_iec559 and std::numeric_limits::digits == 24 and std::numeric_limits::max_exponent == 128) or
(std::numeric_limits::is_iec559 and std::numeric_limits::digits == 53 and std::numeric_limits::max_exponent == 1024);
dump_float(x, std::integral_constant());
}
void dump_float(number_float_t x, std::true_type /*is_ieee_single_or_double*/)
{
char* begin = number_buffer.data();
char* end = ::nlohmann::detail::to_chars(begin, begin + number_buffer.size(), x);
o->write_characters(begin, static_cast(end – begin));
}
void dump_float(number_float_t x, std::false_type /*is_ieee_single_or_double*/)
{
// get number of digits for a float -> text -> float round-trip
static constexpr auto d = std::numeric_limits::max_digits10;
// the actual conversion
std::ptrdiff_t len = (std::snprintf)(number_buffer.data(), number_buffer.size(), “%.*g”, d, x);
// negative value indicates an error
assert(len > 0);
// check if buffer was large enough
assert(static_cast(len) < number_buffer.size());
// erase thousands separator
if (thousands_sep != '\0')
{
const auto end = std::remove(number_buffer.begin(),
number_buffer.begin() + len, thousands_sep);
std::fill(end, number_buffer.end(), '\0');
assert((end - number_buffer.begin()) <= len);
len = (end - number_buffer.begin());
}
// convert decimal point to '.'
if (decimal_point != '\0' and decimal_point != '.')
{
const auto dec_pos = std::find(number_buffer.begin(), number_buffer.end(), decimal_point);
if (dec_pos != number_buffer.end())
{
*dec_pos = '.';
}
}
o->write_characters(number_buffer.data(), static_cast(len));
// determine if need to append “.0”
const bool value_is_int_like =
std::none_of(number_buffer.begin(), number_buffer.begin() + len + 1,
[](char c)
{
return (c == ‘.’ or c == ‘e’);
});
if (value_is_int_like)
{
o->write_characters(“.0”, 2);
}
}
/*!
@brief check whether a string is UTF-8 encoded
The function checks each byte of a string whether it is UTF-8 encoded. The
result of the check is stored in the @a state parameter. The function must
be called initially with state 0 (accept). State 1 means the string must
be rejected, because the current byte is not allowed. If the string is
completely processed, but the state is non-zero, the string ended
prematurely; that is, the last byte indicated more bytes should have
followed.
@param[in,out] state the state of the decoding
@param[in,out] codep codepoint (valid only if resulting state is UTF8_ACCEPT)
@param[in] byte next byte to decode
@return new state
@note The function has been edited: a std::array is used.
@copyright Copyright (c) 2008-2009 Bjoern Hoehrmann
@sa http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
*/
static uint8_t decode(uint8_t& state, uint32_t& codep, const uint8_t byte) noexcept
{
static const std::array utf8d =
{
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 00..1F
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 20..3F
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 40..5F
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 60..7F
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, // 80..9F
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // A0..BF
8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, // C0..DF
0xA, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x4, 0x3, 0x3, // E0..EF
0xB, 0x6, 0x6, 0x6, 0x5, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, // F0..FF
0x0, 0x1, 0x2, 0x3, 0x5, 0x8, 0x7, 0x1, 0x1, 0x1, 0x4, 0x6, 0x1, 0x1, 0x1, 0x1, // s0..s0
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, // s1..s2
1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, // s3..s4
1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, // s5..s6
1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 // s7..s8
}
};
const uint8_t type = utf8d[byte];
codep = (state != UTF8_ACCEPT)
? (byte & 0x3fu) | (codep << 6)
: static_cast(0xff >> type) & (byte);
state = utf8d[256u + state * 16u + type];
return state;
}
private:
/// the output of the serializer
output_adapter_t o = nullptr;
/// a (hopefully) large enough character buffer
std::array number_buffer{{}};
/// the locale
const std::lconv* loc = nullptr;
/// the locale’s thousand separator character
const char thousands_sep = ‘\0’;
/// the locale’s decimal point character
const char decimal_point = ‘\0’;
/// string buffer
std::array string_buffer{{}};
/// the indentation character
const char indent_char;
/// the indentation string
string_t indent_string;
/// error_handler how to react on decoding errors
const error_handler_t error_handler;
};
} // namespace detail
} // namespace nlohmann
// #include
#include
#include
// #include
namespace nlohmann
{
namespace detail
{
template
class json_ref
{
public:
using value_type = BasicJsonType;
json_ref(value_type&& value)
: owned_value(std::move(value)), value_ref(&owned_value), is_rvalue(true)
{}
json_ref(const value_type& value)
: value_ref(const_cast(&value)), is_rvalue(false)
{}
json_ref(std::initializer_list init)
: owned_value(init), value_ref(&owned_value), is_rvalue(true)
{}
template <
class... Args,
enable_if_t::value, int> = 0 >
json_ref(Args && … args)
: owned_value(std::forward(args)…), value_ref(&owned_value),
is_rvalue(true) {}
// class should be movable only
json_ref(json_ref&&) = default;
json_ref(const json_ref&) = delete;
json_ref& operator=(const json_ref&) = delete;
json_ref& operator=(json_ref&&) = delete;
~json_ref() = default;
value_type moved_or_copied() const
{
if (is_rvalue)
{
return std::move(*value_ref);
}
return *value_ref;
}
value_type const& operator*() const
{
return *static_cast(value_ref);
}
value_type const* operator->() const
{
return static_cast(value_ref);
}
private:
mutable value_type owned_value = nullptr;
value_type* value_ref = nullptr;
const bool is_rvalue;
};
} // namespace detail
} // namespace nlohmann
// #include
#include // all_of
#include // assert
#include // accumulate
#include // string
#include // vector
// #include
// #include
// #include
namespace nlohmann
{
template
class json_pointer
{
// allow basic_json to access private members
NLOHMANN_BASIC_JSON_TPL_DECLARATION
friend class basic_json;
public:
/*!
@brief create JSON pointer
Create a JSON pointer according to the syntax described in
[Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3).
@param[in] s string representing the JSON pointer; if omitted, the empty
string is assumed which references the whole JSON value
@throw parse_error.107 if the given JSON pointer @a s is nonempty and does
not begin with a slash (`/`); see example below
@throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s is
not followed by `0` (representing `~`) or `1` (representing `/`); see
example below
@liveexample{The example shows the construction several valid JSON pointers
as well as the exceptional behavior.,json_pointer}
@since version 2.0.0
*/
explicit json_pointer(const std::string& s = “”)
: reference_tokens(split(s))
{}
/*!
@brief return a string representation of the JSON pointer
@invariant For each JSON pointer `ptr`, it holds:
@code {.cpp}
ptr == json_pointer(ptr.to_string());
@endcode
@return a string representation of the JSON pointer
@liveexample{The example shows the result of `to_string`.,
json_pointer__to_string}
@since version 2.0.0
*/
std::string to_string() const
{
return std::accumulate(reference_tokens.begin(), reference_tokens.end(),
std::string{},
[](const std::string & a, const std::string & b)
{
return a + “/” + escape(b);
});
}
/// @copydoc to_string()
operator std::string() const
{
return to_string();
}
/*!
@param[in] s reference token to be converted into an array index
@return integer representation of @a s
@throw out_of_range.404 if string @a s could not be converted to an integer
*/
static int array_index(const std::string& s)
{
std::size_t processed_chars = 0;
const int res = std::stoi(s, &processed_chars);
// check if the string was completely read
if (JSON_UNLIKELY(processed_chars != s.size()))
{
JSON_THROW(detail::out_of_range::create(404, “unresolved reference token ‘” + s + “‘”));
}
return res;
}
/*!
@brief remove and return last reference pointer
@throw out_of_range.405 if JSON pointer has no parent
*/
std::string pop_back()
{
if (JSON_UNLIKELY(is_root()))
{
JSON_THROW(detail::out_of_range::create(405, “JSON pointer has no parent”));
}
auto last = reference_tokens.back();
reference_tokens.pop_back();
return last;
}
/*!
@brief remove and return last reference pointer
@throw out_of_range.405 if JSON pointer has no parent
*/
void push_back(const std::string& tok)
{
reference_tokens.push_back(tok);
}
private:
/// return whether pointer points to the root document
bool is_root() const noexcept
{
return reference_tokens.empty();
}
json_pointer top() const
{
if (JSON_UNLIKELY(is_root()))
{
JSON_THROW(detail::out_of_range::create(405, “JSON pointer has no parent”));
}
json_pointer result = *this;
result.reference_tokens = {reference_tokens[0]};
return result;
}
/*!
@brief create and return a reference to the pointed to value
@complexity Linear in the number of reference tokens.
@throw parse_error.109 if array index is not a number
@throw type_error.313 if value cannot be unflattened
*/
BasicJsonType& get_and_create(BasicJsonType& j) const
{
using size_type = typename BasicJsonType::size_type;
auto result = &j;
// in case no reference tokens exist, return a reference to the JSON value
// j which will be overwritten by a primitive value
for (const auto& reference_token : reference_tokens)
{
switch (result->m_type)
{
case detail::value_t::null:
{
if (reference_token == “0”)
{
// start a new array if reference token is 0
result = &result->operator[](0);
}
else
{
// start a new object otherwise
result = &result->operator[](reference_token);
}
break;
}
case detail::value_t::object:
{
// create an entry in the object
result = &result->operator[](reference_token);
break;
}
case detail::value_t::array:
{
// create an entry in the array
JSON_TRY
{
result = &result->operator[](static_cast(array_index(reference_token)));
}
JSON_CATCH(std::invalid_argument&)
{
JSON_THROW(detail::parse_error::create(109, 0, “array index ‘” + reference_token + “‘ is not a number”));
}
break;
}
/*
The following code is only reached if there exists a reference
token _and_ the current value is primitive. In this case, we have
an error situation, because primitive values may only occur as
single value; that is, with an empty list of reference tokens.
*/
default:
JSON_THROW(detail::type_error::create(313, “invalid value to unflatten”));
}
}
return *result;
}
/*!
@brief return a reference to the pointed to value
@note This version does not throw if a value is not present, but tries to
create nested values instead. For instance, calling this function
with pointer `”/this/that”` on a null value is equivalent to calling
`operator[](“this”).operator[](“that”)` on that value, effectively
changing the null value to an object.
@param[in] ptr a JSON value
@return reference to the JSON value pointed to by the JSON pointer
@complexity Linear in the length of the JSON pointer.
@throw parse_error.106 if an array index begins with ‘0’
@throw parse_error.109 if an array index was not a number
@throw out_of_range.404 if the JSON pointer can not be resolved
*/
BasicJsonType& get_unchecked(BasicJsonType* ptr) const
{
using size_type = typename BasicJsonType::size_type;
for (const auto& reference_token : reference_tokens)
{
// convert null values to arrays or objects before continuing
if (ptr->m_type == detail::value_t::null)
{
// check if reference token is a number
const bool nums =
std::all_of(reference_token.begin(), reference_token.end(),
[](const char x)
{
return (x >= ‘0’ and x <= '9');
});
// change value to array for numbers or "-" or to object otherwise
*ptr = (nums or reference_token == "-")
? detail::value_t::array
: detail::value_t::object;
}
switch (ptr->m_type)
{
case detail::value_t::object:
{
// use unchecked object access
ptr = &ptr->operator[](reference_token);
break;
}
case detail::value_t::array:
{
// error condition (cf. RFC 6901, Sect. 4)
if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == ‘0’))
{
JSON_THROW(detail::parse_error::create(106, 0,
“array index ‘” + reference_token +
“‘ must not begin with ‘0’”));
}
if (reference_token == “-“)
{
// explicitly treat “-” as index beyond the end
ptr = &ptr->operator[](ptr->m_value.array->size());
}
else
{
// convert array index to number; unchecked access
JSON_TRY
{
ptr = &ptr->operator[](
static_cast(array_index(reference_token)));
}
JSON_CATCH(std::invalid_argument&)
{
JSON_THROW(detail::parse_error::create(109, 0, “array index ‘” + reference_token + “‘ is not a number”));
}
}
break;
}
default:
JSON_THROW(detail::out_of_range::create(404, “unresolved reference token ‘” + reference_token + “‘”));
}
}
return *ptr;
}
/*!
@throw parse_error.106 if an array index begins with ‘0’
@throw parse_error.109 if an array index was not a number
@throw out_of_range.402 if the array index ‘-‘ is used
@throw out_of_range.404 if the JSON pointer can not be resolved
*/
BasicJsonType& get_checked(BasicJsonType* ptr) const
{
using size_type = typename BasicJsonType::size_type;
for (const auto& reference_token : reference_tokens)
{
switch (ptr->m_type)
{
case detail::value_t::object:
{
// note: at performs range check
ptr = &ptr->at(reference_token);
break;
}
case detail::value_t::array:
{
if (JSON_UNLIKELY(reference_token == “-“))
{
// “-” always fails the range check
JSON_THROW(detail::out_of_range::create(402,
“array index ‘-‘ (” + std::to_string(ptr->m_value.array->size()) +
“) is out of range”));
}
// error condition (cf. RFC 6901, Sect. 4)
if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == ‘0’))
{
JSON_THROW(detail::parse_error::create(106, 0,
“array index ‘” + reference_token +
“‘ must not begin with ‘0’”));
}
// note: at performs range check
JSON_TRY
{
ptr = &ptr->at(static_cast(array_index(reference_token)));
}
JSON_CATCH(std::invalid_argument&)
{
JSON_THROW(detail::parse_error::create(109, 0, “array index ‘” + reference_token + “‘ is not a number”));
}
break;
}
default:
JSON_THROW(detail::out_of_range::create(404, “unresolved reference token ‘” + reference_token + “‘”));
}
}
return *ptr;
}
/*!
@brief return a const reference to the pointed to value
@param[in] ptr a JSON value
@return const reference to the JSON value pointed to by the JSON
pointer
@throw parse_error.106 if an array index begins with ‘0’
@throw parse_error.109 if an array index was not a number
@throw out_of_range.402 if the array index ‘-‘ is used
@throw out_of_range.404 if the JSON pointer can not be resolved
*/
const BasicJsonType& get_unchecked(const BasicJsonType* ptr) const
{
using size_type = typename BasicJsonType::size_type;
for (const auto& reference_token : reference_tokens)
{
switch (ptr->m_type)
{
case detail::value_t::object:
{
// use unchecked object access
ptr = &ptr->operator[](reference_token);
break;
}
case detail::value_t::array:
{
if (JSON_UNLIKELY(reference_token == “-“))
{
// “-” cannot be used for const access
JSON_THROW(detail::out_of_range::create(402,
“array index ‘-‘ (” + std::to_string(ptr->m_value.array->size()) +
“) is out of range”));
}
// error condition (cf. RFC 6901, Sect. 4)
if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == ‘0’))
{
JSON_THROW(detail::parse_error::create(106, 0,
“array index ‘” + reference_token +
“‘ must not begin with ‘0’”));
}
// use unchecked array access
JSON_TRY
{
ptr = &ptr->operator[](
static_cast(array_index(reference_token)));
}
JSON_CATCH(std::invalid_argument&)
{
JSON_THROW(detail::parse_error::create(109, 0, “array index ‘” + reference_token + “‘ is not a number”));
}
break;
}
default:
JSON_THROW(detail::out_of_range::create(404, “unresolved reference token ‘” + reference_token + “‘”));
}
}
return *ptr;
}
/*!
@throw parse_error.106 if an array index begins with ‘0’
@throw parse_error.109 if an array index was not a number
@throw out_of_range.402 if the array index ‘-‘ is used
@throw out_of_range.404 if the JSON pointer can not be resolved
*/
const BasicJsonType& get_checked(const BasicJsonType* ptr) const
{
using size_type = typename BasicJsonType::size_type;
for (const auto& reference_token : reference_tokens)
{
switch (ptr->m_type)
{
case detail::value_t::object:
{
// note: at performs range check
ptr = &ptr->at(reference_token);
break;
}
case detail::value_t::array:
{
if (JSON_UNLIKELY(reference_token == “-“))
{
// “-” always fails the range check
JSON_THROW(detail::out_of_range::create(402,
“array index ‘-‘ (” + std::to_string(ptr->m_value.array->size()) +
“) is out of range”));
}
// error condition (cf. RFC 6901, Sect. 4)
if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == ‘0’))
{
JSON_THROW(detail::parse_error::create(106, 0,
“array index ‘” + reference_token +
“‘ must not begin with ‘0’”));
}
// note: at performs range check
JSON_TRY
{
ptr = &ptr->at(static_cast(array_index(reference_token)));
}
JSON_CATCH(std::invalid_argument&)
{
JSON_THROW(detail::parse_error::create(109, 0, “array index ‘” + reference_token + “‘ is not a number”));
}
break;
}
default:
JSON_THROW(detail::out_of_range::create(404, “unresolved reference token ‘” + reference_token + “‘”));
}
}
return *ptr;
}
/*!
@brief split the string input to reference tokens
@note This function is only called by the json_pointer constructor.
All exceptions below are documented there.
@throw parse_error.107 if the pointer is not empty or begins with ‘/’
@throw parse_error.108 if character ‘~’ is not followed by ‘0’ or ‘1’
*/
static std::vector split(const std::string& reference_string)
{
std::vector result;
// special case: empty reference string -> no reference tokens
if (reference_string.empty())
{
return result;
}
// check if nonempty reference string begins with slash
if (JSON_UNLIKELY(reference_string[0] != ‘/’))
{
JSON_THROW(detail::parse_error::create(107, 1,
“JSON pointer must be empty or begin with ‘/’ – was: ‘” +
reference_string + “‘”));
}
// extract the reference tokens:
// – slash: position of the last read slash (or end of string)
// – start: position after the previous slash
for (
// search for the first slash after the first character
std::size_t slash = reference_string.find_first_of(‘/’, 1),
// set the beginning of the first reference token
start = 1;
// we can stop if start == 0 (if slash == std::string::npos)
start != 0;
// set the beginning of the next reference token
// (will eventually be 0 if slash == std::string::npos)
start = (slash == std::string::npos) ? 0 : slash + 1,
// find next slash
slash = reference_string.find_first_of(‘/’, start))
{
// use the text between the beginning of the reference token
// (start) and the last slash (slash).
auto reference_token = reference_string.substr(start, slash – start);
// check reference tokens are properly escaped
for (std::size_t pos = reference_token.find_first_of(‘~’);
pos != std::string::npos;
pos = reference_token.find_first_of(‘~’, pos + 1))
{
assert(reference_token[pos] == ‘~’);
// ~ must be followed by 0 or 1
if (JSON_UNLIKELY(pos == reference_token.size() – 1 or
(reference_token[pos + 1] != ‘0’ and
reference_token[pos + 1] != ‘1’)))
{
JSON_THROW(detail::parse_error::create(108, 0, “escape character ‘~’ must be followed with ‘0’ or ‘1’”));
}
}
// finally, store the reference token
unescape(reference_token);
result.push_back(reference_token);
}
return result;
}
/*!
@brief replace all occurrences of a substring by another string
@param[in,out] s the string to manipulate; changed so that all
occurrences of @a f are replaced with @a t
@param[in] f the substring to replace with @a t
@param[in] t the string to replace @a f
@pre The search string @a f must not be empty. **This precondition is
enforced with an assertion.**
@since version 2.0.0
*/
static void replace_substring(std::string& s, const std::string& f,
const std::string& t)
{
assert(not f.empty());
for (auto pos = s.find(f); // find first occurrence of f
pos != std::string::npos; // make sure f was found
s.replace(pos, f.size(), t), // replace with t, and
pos = s.find(f, pos + t.size())) // find next occurrence of f
{}
}
/// escape “~” to “~0” and “/” to “~1”
static std::string escape(std::string s)
{
replace_substring(s, “~”, “~0”);
replace_substring(s, “/”, “~1”);
return s;
}
/// unescape “~1” to tilde and “~0” to slash (order is important!)
static void unescape(std::string& s)
{
replace_substring(s, “~1”, “/”);
replace_substring(s, “~0”, “~”);
}
/*!
@param[in] reference_string the reference string to the current value
@param[in] value the value to consider
@param[in,out] result the result object to insert values to
@note Empty objects or arrays are flattened to `null`.
*/
static void flatten(const std::string& reference_string,
const BasicJsonType& value,
BasicJsonType& result)
{
switch (value.m_type)
{
case detail::value_t::array:
{
if (value.m_value.array->empty())
{
// flatten empty array as null
result[reference_string] = nullptr;
}
else
{
// iterate array and use index as reference string
for (std::size_t i = 0; i < value.m_value.array->size(); ++i)
{
flatten(reference_string + “/” + std::to_string(i),
value.m_value.array->operator[](i), result);
}
}
break;
}
case detail::value_t::object:
{
if (value.m_value.object->empty())
{
// flatten empty object as null
result[reference_string] = nullptr;
}
else
{
// iterate object and use keys as reference string
for (const auto& element : *value.m_value.object)
{
flatten(reference_string + “/” + escape(element.first), element.second, result);
}
}
break;
}
default:
{
// add primitive value with its reference string
result[reference_string] = value;
break;
}
}
}
/*!
@param[in] value flattened JSON
@return unflattened JSON
@throw parse_error.109 if array index is not a number
@throw type_error.314 if value is not an object
@throw type_error.315 if object values are not primitive
@throw type_error.313 if value cannot be unflattened
*/
static BasicJsonType
unflatten(const BasicJsonType& value)
{
if (JSON_UNLIKELY(not value.is_object()))
{
JSON_THROW(detail::type_error::create(314, “only objects can be unflattened”));
}
BasicJsonType result;
// iterate the JSON object values
for (const auto& element : *value.m_value.object)
{
if (JSON_UNLIKELY(not element.second.is_primitive()))
{
JSON_THROW(detail::type_error::create(315, “values in object must be primitive”));
}
// assign value to reference pointed to by JSON pointer; Note that if
// the JSON pointer is “” (i.e., points to the whole value), function
// get_and_create returns a reference to result itself. An assignment
// will then create a primitive value.
json_pointer(element.first).get_and_create(result) = element.second;
}
return result;
}
friend bool operator==(json_pointer const& lhs,
json_pointer const& rhs) noexcept
{
return (lhs.reference_tokens == rhs.reference_tokens);
}
friend bool operator!=(json_pointer const& lhs,
json_pointer const& rhs) noexcept
{
return not (lhs == rhs);
}
/// the reference tokens
std::vector reference_tokens;
};
} // namespace nlohmann
// #include
#include
// #include
// #include
namespace nlohmann
{
template
struct adl_serializer
{
/*!
@brief convert a JSON value to any value type
This function is usually called by the `get()` function of the
@ref basic_json class (either explicit or via conversion operators).
@param[in] j JSON value to read from
@param[in,out] val value to write to
*/
template
static auto from_json(BasicJsonType&& j, ValueType& val) noexcept(
noexcept(::nlohmann::from_json(std::forward(j), val)))
-> decltype(::nlohmann::from_json(std::forward(j), val), void())
{
::nlohmann::from_json(std::forward(j), val);
}
/*!
@brief convert any value type to a JSON value
This function is usually called by the constructors of the @ref basic_json
class.
@param[in,out] j JSON value to write to
@param[in] val value to read from
*/
template
static auto to_json(BasicJsonType& j, ValueType&& val) noexcept(
noexcept(::nlohmann::to_json(j, std::forward(val))))
-> decltype(::nlohmann::to_json(j, std::forward(val)), void())
{
::nlohmann::to_json(j, std::forward(val));
}
};
} // namespace nlohmann
/*!
@brief namespace for Niels Lohmann
@see https://github.com/nlohmann
@since version 1.0.0
*/
namespace nlohmann
{
/*!
@brief a class to store JSON values
@tparam ObjectType type for JSON objects (`std::map` by default; will be used
in @ref object_t)
@tparam ArrayType type for JSON arrays (`std::vector` by default; will be used
in @ref array_t)
@tparam StringType type for JSON strings and object keys (`std::string` by
default; will be used in @ref string_t)
@tparam BooleanType type for JSON booleans (`bool` by default; will be used
in @ref boolean_t)
@tparam NumberIntegerType type for JSON integer numbers (`int64_t` by
default; will be used in @ref number_integer_t)
@tparam NumberUnsignedType type for JSON unsigned integer numbers (@c
`uint64_t` by default; will be used in @ref number_unsigned_t)
@tparam NumberFloatType type for JSON floating-point numbers (`double` by
default; will be used in @ref number_float_t)
@tparam AllocatorType type of the allocator to use (`std::allocator` by
default)
@tparam JSONSerializer the serializer to resolve internal calls to `to_json()`
and `from_json()` (@ref adl_serializer by default)
@requirement The class satisfies the following concept requirements:
– Basic
– [DefaultConstructible](https://en.cppreference.com/w/cpp/named_req/DefaultConstructible):
JSON values can be default constructed. The result will be a JSON null
value.
– [MoveConstructible](https://en.cppreference.com/w/cpp/named_req/MoveConstructible):
A JSON value can be constructed from an rvalue argument.
– [CopyConstructible](https://en.cppreference.com/w/cpp/named_req/CopyConstructible):
A JSON value can be copy-constructed from an lvalue expression.
– [MoveAssignable](https://en.cppreference.com/w/cpp/named_req/MoveAssignable):
A JSON value van be assigned from an rvalue argument.
– [CopyAssignable](https://en.cppreference.com/w/cpp/named_req/CopyAssignable):
A JSON value can be copy-assigned from an lvalue expression.
– [Destructible](https://en.cppreference.com/w/cpp/named_req/Destructible):
JSON values can be destructed.
– Layout
– [StandardLayoutType](https://en.cppreference.com/w/cpp/named_req/StandardLayoutType):
JSON values have
[standard layout](https://en.cppreference.com/w/cpp/language/data_members#Standard_layout):
All non-static data members are private and standard layout types, the
class has no virtual functions or (virtual) base classes.
– Library-wide
– [EqualityComparable](https://en.cppreference.com/w/cpp/named_req/EqualityComparable):
JSON values can be compared with `==`, see @ref
operator==(const_reference,const_reference).
– [LessThanComparable](https://en.cppreference.com/w/cpp/named_req/LessThanComparable):
JSON values can be compared with `<`, see @ref
operator<(const_reference,const_reference).
- [Swappable](https://en.cppreference.com/w/cpp/named_req/Swappable):
Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of
other compatible types, using unqualified function call @ref swap().
- [NullablePointer](https://en.cppreference.com/w/cpp/named_req/NullablePointer):
JSON values can be compared against `std::nullptr_t` objects which are used
to model the `null` value.
- Container
- [Container](https://en.cppreference.com/w/cpp/named_req/Container):
JSON values can be used like STL containers and provide iterator access.
- [ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer);
JSON values can be used like STL containers and provide reverse iterator
access.
@invariant The member variables @a m_value and @a m_type have the following
relationship:
- If `m_type == value_t::object`, then `m_value.object != nullptr`.
- If `m_type == value_t::array`, then `m_value.array != nullptr`.
- If `m_type == value_t::string`, then `m_value.string != nullptr`.
The invariants are checked by member function assert_invariant().
@internal
@note ObjectType trick from http://stackoverflow.com/a/9860911
@endinternal
@see [RFC 7159: The JavaScript Object Notation (JSON) Data Interchange
Format](http://rfc7159.net/rfc7159)
@since version 1.0.0
@nosubgrouping
*/
NLOHMANN_BASIC_JSON_TPL_DECLARATION
class basic_json
{
private:
template friend struct detail::external_constructor;
friend ::nlohmann::json_pointer;
friend ::nlohmann::detail::parser;
friend ::nlohmann::detail::serializer;
template
friend class ::nlohmann::detail::iter_impl;
template
friend class ::nlohmann::detail::binary_writer;
template
friend class ::nlohmann::detail::binary_reader;
template
friend class ::nlohmann::detail::json_sax_dom_parser;
template
friend class ::nlohmann::detail::json_sax_dom_callback_parser;
/// workaround type for MSVC
using basic_json_t = NLOHMANN_BASIC_JSON_TPL;
// convenience aliases for types residing in namespace detail;
using lexer = ::nlohmann::detail::lexer;
using parser = ::nlohmann::detail::parser;
using primitive_iterator_t = ::nlohmann::detail::primitive_iterator_t;
template
using internal_iterator = ::nlohmann::detail::internal_iterator;
template
using iter_impl = ::nlohmann::detail::iter_impl;
template
using iteration_proxy = ::nlohmann::detail::iteration_proxy;
template using json_reverse_iterator = ::nlohmann::detail::json_reverse_iterator;
template
using output_adapter_t = ::nlohmann::detail::output_adapter_t;
using binary_reader = ::nlohmann::detail::binary_reader;
template using binary_writer = ::nlohmann::detail::binary_writer;
using serializer = ::nlohmann::detail::serializer;
public:
using value_t = detail::value_t;
/// JSON Pointer, see @ref nlohmann::json_pointer
using json_pointer = ::nlohmann::json_pointer;
template
using json_serializer = JSONSerializer;
/// how to treat decoding errors
using error_handler_t = detail::error_handler_t;
/// helper type for initializer lists of basic_json values
using initializer_list_t = std::initializer_list>;
using input_format_t = detail::input_format_t;
/// SAX interface type, see @ref nlohmann::json_sax
using json_sax_t = json_sax;
////////////////
// exceptions //
////////////////
/// @name exceptions
/// Classes to implement user-defined exceptions.
/// @{
/// @copydoc detail::exception
using exception = detail::exception;
/// @copydoc detail::parse_error
using parse_error = detail::parse_error;
/// @copydoc detail::invalid_iterator
using invalid_iterator = detail::invalid_iterator;
/// @copydoc detail::type_error
using type_error = detail::type_error;
/// @copydoc detail::out_of_range
using out_of_range = detail::out_of_range;
/// @copydoc detail::other_error
using other_error = detail::other_error;
/// @}
/////////////////////
// container types //
/////////////////////
/// @name container types
/// The canonic container types to use @ref basic_json like any other STL
/// container.
/// @{
/// the type of elements in a basic_json container
using value_type = basic_json;
/// the type of an element reference
using reference = value_type&;
/// the type of an element const reference
using const_reference = const value_type&;
/// a type to represent differences between iterators
using difference_type = std::ptrdiff_t;
/// a type to represent container sizes
using size_type = std::size_t;
/// the allocator type
using allocator_type = AllocatorType;
/// the type of an element pointer
using pointer = typename std::allocator_traits::pointer;
/// the type of an element const pointer
using const_pointer = typename std::allocator_traits::const_pointer;
/// an iterator for a basic_json container
using iterator = iter_impl;
/// a const iterator for a basic_json container
using const_iterator = iter_impl;
/// a reverse iterator for a basic_json container
using reverse_iterator = json_reverse_iterator;
/// a const reverse iterator for a basic_json container
using const_reverse_iterator = json_reverse_iterator;
/// @}
/*!
@brief returns the allocator associated with the container
*/
static allocator_type get_allocator()
{
return allocator_type();
}
/*!
@brief returns version information on the library
This function returns a JSON object with information about the library,
including the version number and information on the platform and compiler.
@return JSON object holding version information
key | description
———– | —————
`compiler` | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version).
`copyright` | The copyright line for the library as string.
`name` | The name of the library as string.
`platform` | The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`.
`url` | The URL of the project as string.
`version` | The version of the library. It is an object with the following keys: `major`, `minor`, and `patch` as defined by [Semantic Versioning](http://semver.org), and `string` (the version string).
@liveexample{The following code shows an example output of the `meta()`
function.,meta}
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes to any JSON value.
@complexity Constant.
@since 2.1.0
*/
JSON_NODISCARD
static basic_json meta()
{
basic_json result;
result[“copyright”] = “(C) 2013-2017 Niels Lohmann”;
result[“name”] = “JSON for Modern C++”;
result[“url”] = “https://github.com/nlohmann/json”;
result[“version”][“string”] =
std::to_string(NLOHMANN_JSON_VERSION_MAJOR) + “.” +
std::to_string(NLOHMANN_JSON_VERSION_MINOR) + “.” +
std::to_string(NLOHMANN_JSON_VERSION_PATCH);
result[“version”][“major”] = NLOHMANN_JSON_VERSION_MAJOR;
result[“version”][“minor”] = NLOHMANN_JSON_VERSION_MINOR;
result[“version”][“patch”] = NLOHMANN_JSON_VERSION_PATCH;
#ifdef _WIN32
result[“platform”] = “win32”;
#elif defined __linux__
result[“platform”] = “linux”;
#elif defined __APPLE__
result[“platform”] = “apple”;
#elif defined __unix__
result[“platform”] = “unix”;
#else
result[“platform”] = “unknown”;
#endif
#if defined(__ICC) || defined(__INTEL_COMPILER)
result[“compiler”] = {{“family”, “icc”}, {“version”, __INTEL_COMPILER}};
#elif defined(__clang__)
result[“compiler”] = {{“family”, “clang”}, {“version”, __clang_version__}};
#elif defined(__GNUC__) || defined(__GNUG__)
result[“compiler”] = {{“family”, “gcc”}, {“version”, std::to_string(__GNUC__) + “.” + std::to_string(__GNUC_MINOR__) + “.” + std::to_string(__GNUC_PATCHLEVEL__)}};
#elif defined(__HP_cc) || defined(__HP_aCC)
result[“compiler”] = “hp”
#elif defined(__IBMCPP__)
result[“compiler”] = {{“family”, “ilecpp”}, {“version”, __IBMCPP__}};
#elif defined(_MSC_VER)
result[“compiler”] = {{“family”, “msvc”}, {“version”, _MSC_VER}};
#elif defined(__PGI)
result[“compiler”] = {{“family”, “pgcpp”}, {“version”, __PGI}};
#elif defined(__SUNPRO_CC)
result[“compiler”] = {{“family”, “sunpro”}, {“version”, __SUNPRO_CC}};
#else
result[“compiler”] = {{“family”, “unknown”}, {“version”, “unknown”}};
#endif
#ifdef __cplusplus
result[“compiler”][“c++”] = std::to_string(__cplusplus);
#else
result[“compiler”][“c++”] = “unknown”;
#endif
return result;
}
///////////////////////////
// JSON value data types //
///////////////////////////
/// @name JSON value data types
/// The data types to store a JSON value. These types are derived from
/// the template arguments passed to class @ref basic_json.
/// @{
#if defined(JSON_HAS_CPP_14)
// Use transparent comparator if possible, combined with perfect forwarding
// on find() and count() calls prevents unnecessary string construction.
using object_comparator_t = std::less<>;
#else
using object_comparator_t = std::less;
#endif
/*!
@brief a type for an object
[RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows:
> An object is an unordered collection of zero or more name/value pairs,
> where a name is a string and a value is a string, number, boolean, null,
> object, or array.
To store objects in C++, a type is defined by the template parameters
described below.
@tparam ObjectType the container to store objects (e.g., `std::map` or
`std::unordered_map`)
@tparam StringType the type of the keys or names (e.g., `std::string`).
The comparison function `std::less` is used to order elements
inside the container.
@tparam AllocatorType the allocator to use for objects (e.g.,
`std::allocator`)
#### Default type
With the default values for @a ObjectType (`std::map`), @a StringType
(`std::string`), and @a AllocatorType (`std::allocator`), the default
value for @a object_t is:
@code {.cpp}
std::map<
std::string, // key_type
basic_json, // value_type
std::less, // key_compare
std::allocator> // allocator_type
>
@endcode
#### Behavior
The choice of @a object_t influences the behavior of the JSON class. With
the default type, objects have the following behavior:
– When all names are unique, objects will be interoperable in the sense
that all software implementations receiving that object will agree on
the name-value mappings.
– When the names within an object are not unique, it is unspecified which
one of the values for a given key will be chosen. For instance,
`{“key”: 2, “key”: 1}` could be equal to either `{“key”: 1}` or
`{“key”: 2}`.
– Internally, name/value pairs are stored in lexicographical order of the
names. Objects will also be serialized (see @ref dump) in this order.
For instance, `{“b”: 1, “a”: 2}` and `{“a”: 2, “b”: 1}` will be stored
and serialized as `{“a”: 2, “b”: 1}`.
– When comparing objects, the order of the name/value pairs is irrelevant.
This makes objects interoperable in the sense that they will not be
affected by these differences. For instance, `{“b”: 1, “a”: 2}` and
`{“a”: 2, “b”: 1}` will be treated as equal.
#### Limits
[RFC 7159](http://rfc7159.net/rfc7159) specifies:
> An implementation may set limits on the maximum depth of nesting.
In this class, the object’s limit of nesting is not explicitly constrained.
However, a maximum depth of nesting may be introduced by the compiler or
runtime environment. A theoretical limit can be queried by calling the
@ref max_size function of a JSON object.
#### Storage
Objects are stored as pointers in a @ref basic_json type. That is, for any
access to object values, a pointer of type `object_t*` must be
dereferenced.
@sa @ref array_t — type for an array value
@since version 1.0.0
@note The order name/value pairs are added to the object is *not*
preserved by the library. Therefore, iterating an object may return
name/value pairs in a different order than they were originally stored. In
fact, keys will be traversed in alphabetical order as `std::map` with
`std::less` is used by default. Please note this behavior conforms to [RFC
7159](http://rfc7159.net/rfc7159), because any order implements the
specified “unordered” nature of JSON objects.
*/
using object_t = ObjectType>>;
/*!
@brief a type for an array
[RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows:
> An array is an ordered sequence of zero or more values.
To store objects in C++, a type is defined by the template parameters
explained below.
@tparam ArrayType container type to store arrays (e.g., `std::vector` or
`std::list`)
@tparam AllocatorType allocator to use for arrays (e.g., `std::allocator`)
#### Default type
With the default values for @a ArrayType (`std::vector`) and @a
AllocatorType (`std::allocator`), the default value for @a array_t is:
@code {.cpp}
std::vector<
basic_json, // value_type
std::allocator // allocator_type
>
@endcode
#### Limits
[RFC 7159](http://rfc7159.net/rfc7159) specifies:
> An implementation may set limits on the maximum depth of nesting.
In this class, the array’s limit of nesting is not explicitly constrained.
However, a maximum depth of nesting may be introduced by the compiler or
runtime environment. A theoretical limit can be queried by calling the
@ref max_size function of a JSON array.
#### Storage
Arrays are stored as pointers in a @ref basic_json type. That is, for any
access to array values, a pointer of type `array_t*` must be dereferenced.
@sa @ref object_t — type for an object value
@since version 1.0.0
*/
using array_t = ArrayType>;
/*!
@brief a type for a string
[RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows:
> A string is a sequence of zero or more Unicode characters.
To store objects in C++, a type is defined by the template parameter
described below. Unicode values are split by the JSON class into
byte-sized characters during deserialization.
@tparam StringType the container to store strings (e.g., `std::string`).
Note this container is used for keys/names in objects, see @ref object_t.
#### Default type
With the default values for @a StringType (`std::string`), the default
value for @a string_t is:
@code {.cpp}
std::string
@endcode
#### Encoding
Strings are stored in UTF-8 encoding. Therefore, functions like
`std::string::size()` or `std::string::length()` return the number of
bytes in the string rather than the number of characters or glyphs.
#### String comparison
[RFC 7159](http://rfc7159.net/rfc7159) states:
> Software implementations are typically required to test names of object
> members for equality. Implementations that transform the textual
> representation into sequences of Unicode code units and then perform the
> comparison numerically, code unit by code unit, are interoperable in the
> sense that implementations will agree in all cases on equality or
> inequality of two strings. For example, implementations that compare
> strings with escaped characters unconverted may incorrectly find that
> `”a\\b”` and `”a\u005Cb”` are not equal.
This implementation is interoperable as it does compare strings code unit
by code unit.
#### Storage
String values are stored as pointers in a @ref basic_json type. That is,
for any access to string values, a pointer of type `string_t*` must be
dereferenced.
@since version 1.0.0
*/
using string_t = StringType;
/*!
@brief a type for a boolean
[RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a
type which differentiates the two literals `true` and `false`.
To store objects in C++, a type is defined by the template parameter @a
BooleanType which chooses the type to use.
#### Default type
With the default values for @a BooleanType (`bool`), the default value for
@a boolean_t is:
@code {.cpp}
bool
@endcode
#### Storage
Boolean values are stored directly inside a @ref basic_json type.
@since version 1.0.0
*/
using boolean_t = BooleanType;
/*!
@brief a type for a number (integer)
[RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows:
> The representation of numbers is similar to that used in most
> programming languages. A number is represented in base 10 using decimal
> digits. It contains an integer component that may be prefixed with an
> optional minus sign, which may be followed by a fraction part and/or an
> exponent part. Leading zeros are not allowed. (…) Numeric values that
> cannot be represented in the grammar below (such as Infinity and NaN)
> are not permitted.
This description includes both integer and floating-point numbers.
However, C++ allows more precise storage if it is known whether the number
is a signed integer, an unsigned integer or a floating-point number.
Therefore, three different types, @ref number_integer_t, @ref
number_unsigned_t and @ref number_float_t are used.
To store integer numbers in C++, a type is defined by the template
parameter @a NumberIntegerType which chooses the type to use.
#### Default type
With the default values for @a NumberIntegerType (`int64_t`), the default
value for @a number_integer_t is:
@code {.cpp}
int64_t
@endcode
#### Default behavior
– The restrictions about leading zeros is not enforced in C++. Instead,
leading zeros in integer literals lead to an interpretation as octal
number. Internally, the value will be stored as decimal number. For
instance, the C++ integer literal `010` will be serialized to `8`.
During deserialization, leading zeros yield an error.
– Not-a-number (NaN) values will be serialized to `null`.
#### Limits
[RFC 7159](http://rfc7159.net/rfc7159) specifies:
> An implementation may set limits on the range and precision of numbers.
When the default type is used, the maximal integer number that can be
stored is `9223372036854775807` (INT64_MAX) and the minimal integer number
that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers
that are out of range will yield over/underflow when used in a
constructor. During deserialization, too large or small integer numbers
will be automatically be stored as @ref number_unsigned_t or @ref
number_float_t.
[RFC 7159](http://rfc7159.net/rfc7159) further states:
> Note that when such software is used, numbers that are integers and are
> in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense
> that implementations will agree exactly on their numeric values.
As this range is a subrange of the exactly supported range [INT64_MIN,
INT64_MAX], this class’s integer type is interoperable.
#### Storage
Integer number values are stored directly inside a @ref basic_json type.
@sa @ref number_float_t — type for number values (floating-point)
@sa @ref number_unsigned_t — type for number values (unsigned integer)
@since version 1.0.0
*/
using number_integer_t = NumberIntegerType;
/*!
@brief a type for a number (unsigned)
[RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows:
> The representation of numbers is similar to that used in most
> programming languages. A number is represented in base 10 using decimal
> digits. It contains an integer component that may be prefixed with an
> optional minus sign, which may be followed by a fraction part and/or an
> exponent part. Leading zeros are not allowed. (…) Numeric values that
> cannot be represented in the grammar below (such as Infinity and NaN)
> are not permitted.
This description includes both integer and floating-point numbers.
However, C++ allows more precise storage if it is known whether the number
is a signed integer, an unsigned integer or a floating-point number.
Therefore, three different types, @ref number_integer_t, @ref
number_unsigned_t and @ref number_float_t are used.
To store unsigned integer numbers in C++, a type is defined by the
template parameter @a NumberUnsignedType which chooses the type to use.
#### Default type
With the default values for @a NumberUnsignedType (`uint64_t`), the
default value for @a number_unsigned_t is:
@code {.cpp}
uint64_t
@endcode
#### Default behavior
– The restrictions about leading zeros is not enforced in C++. Instead,
leading zeros in integer literals lead to an interpretation as octal
number. Internally, the value will be stored as decimal number. For
instance, the C++ integer literal `010` will be serialized to `8`.
During deserialization, leading zeros yield an error.
– Not-a-number (NaN) values will be serialized to `null`.
#### Limits
[RFC 7159](http://rfc7159.net/rfc7159) specifies:
> An implementation may set limits on the range and precision of numbers.
When the default type is used, the maximal integer number that can be
stored is `18446744073709551615` (UINT64_MAX) and the minimal integer
number that can be stored is `0`. Integer numbers that are out of range
will yield over/underflow when used in a constructor. During
deserialization, too large or small integer numbers will be automatically
be stored as @ref number_integer_t or @ref number_float_t.
[RFC 7159](http://rfc7159.net/rfc7159) further states:
> Note that when such software is used, numbers that are integers and are
> in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense
> that implementations will agree exactly on their numeric values.
As this range is a subrange (when considered in conjunction with the
number_integer_t type) of the exactly supported range [0, UINT64_MAX],
this class’s integer type is interoperable.
#### Storage
Integer number values are stored directly inside a @ref basic_json type.
@sa @ref number_float_t — type for number values (floating-point)
@sa @ref number_integer_t — type for number values (integer)
@since version 2.0.0
*/
using number_unsigned_t = NumberUnsignedType;
/*!
@brief a type for a number (floating-point)
[RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows:
> The representation of numbers is similar to that used in most
> programming languages. A number is represented in base 10 using decimal
> digits. It contains an integer component that may be prefixed with an
> optional minus sign, which may be followed by a fraction part and/or an
> exponent part. Leading zeros are not allowed. (…) Numeric values that
> cannot be represented in the grammar below (such as Infinity and NaN)
> are not permitted.
This description includes both integer and floating-point numbers.
However, C++ allows more precise storage if it is known whether the number
is a signed integer, an unsigned integer or a floating-point number.
Therefore, three different types, @ref number_integer_t, @ref
number_unsigned_t and @ref number_float_t are used.
To store floating-point numbers in C++, a type is defined by the template
parameter @a NumberFloatType which chooses the type to use.
#### Default type
With the default values for @a NumberFloatType (`double`), the default
value for @a number_float_t is:
@code {.cpp}
double
@endcode
#### Default behavior
– The restrictions about leading zeros is not enforced in C++. Instead,
leading zeros in floating-point literals will be ignored. Internally,
the value will be stored as decimal number. For instance, the C++
floating-point literal `01.2` will be serialized to `1.2`. During
deserialization, leading zeros yield an error.
– Not-a-number (NaN) values will be serialized to `null`.
#### Limits
[RFC 7159](http://rfc7159.net/rfc7159) states:
> This specification allows implementations to set limits on the range and
> precision of numbers accepted. Since software that implements IEEE
> 754-2008 binary64 (double precision) numbers is generally available and
> widely used, good interoperability can be achieved by implementations
> that expect no more precision or range than these provide, in the sense
> that implementations will approximate JSON numbers within the expected
> precision.
This implementation does exactly follow this approach, as it uses double
precision floating-point numbers. Note values smaller than
`-1.79769313486232e+308` and values greater than `1.79769313486232e+308`
will be stored as NaN internally and be serialized to `null`.
#### Storage
Floating-point number values are stored directly inside a @ref basic_json
type.
@sa @ref number_integer_t — type for number values (integer)
@sa @ref number_unsigned_t — type for number values (unsigned integer)
@since version 1.0.0
*/
using number_float_t = NumberFloatType;
/// @}
private:
/// helper for exception-safe object creation
template
static T* create(Args&& … args)
{
AllocatorType alloc;
using AllocatorTraits = std::allocator_traits>;
auto deleter = [&](T * object)
{
AllocatorTraits::deallocate(alloc, object, 1);
};
std::unique_ptr object(AllocatorTraits::allocate(alloc, 1), deleter);
AllocatorTraits::construct(alloc, object.get(), std::forward(args)…);
assert(object != nullptr);
return object.release();
}
////////////////////////
// JSON value storage //
////////////////////////
/*!
@brief a JSON value
The actual storage for a JSON value of the @ref basic_json class. This
union combines the different storage types for the JSON value types
defined in @ref value_t.
JSON type | value_t type | used type
——— | ————— | ————————
object | object | pointer to @ref object_t
array | array | pointer to @ref array_t
string | string | pointer to @ref string_t
boolean | boolean | @ref boolean_t
number | number_integer | @ref number_integer_t
number | number_unsigned | @ref number_unsigned_t
number | number_float | @ref number_float_t
null | null | *no value is stored*
@note Variable-length types (objects, arrays, and strings) are stored as
pointers. The size of the union should not exceed 64 bits if the default
value types are used.
@since version 1.0.0
*/
union json_value
{
/// object (stored with pointer to save storage)
object_t* object;
/// array (stored with pointer to save storage)
array_t* array;
/// string (stored with pointer to save storage)
string_t* string;
/// boolean
boolean_t boolean;
/// number (integer)
number_integer_t number_integer;
/// number (unsigned integer)
number_unsigned_t number_unsigned;
/// number (floating-point)
number_float_t number_float;
/// default constructor (for null values)
json_value() = default;
/// constructor for booleans
json_value(boolean_t v) noexcept : boolean(v) {}
/// constructor for numbers (integer)
json_value(number_integer_t v) noexcept : number_integer(v) {}
/// constructor for numbers (unsigned)
json_value(number_unsigned_t v) noexcept : number_unsigned(v) {}
/// constructor for numbers (floating-point)
json_value(number_float_t v) noexcept : number_float(v) {}
/// constructor for empty values of a given type
json_value(value_t t)
{
switch (t)
{
case value_t::object:
{
object = create();
break;
}
case value_t::array:
{
array = create();
break;
}
case value_t::string:
{
string = create(“”);
break;
}
case value_t::boolean:
{
boolean = boolean_t(false);
break;
}
case value_t::number_integer:
{
number_integer = number_integer_t(0);
break;
}
case value_t::number_unsigned:
{
number_unsigned = number_unsigned_t(0);
break;
}
case value_t::number_float:
{
number_float = number_float_t(0.0);
break;
}
case value_t::null:
{
object = nullptr; // silence warning, see #821
break;
}
default:
{
object = nullptr; // silence warning, see #821
if (JSON_UNLIKELY(t == value_t::null))
{
JSON_THROW(other_error::create(500, “961c151d2e87f2686a955a9be24d316f1362bf21 3.5.0”)); // LCOV_EXCL_LINE
}
break;
}
}
}
/// constructor for strings
json_value(const string_t& value)
{
string = create(value);
}
/// constructor for rvalue strings
json_value(string_t&& value)
{
string = create(std::move(value));
}
/// constructor for objects
json_value(const object_t& value)
{
object = create(value);
}
/// constructor for rvalue objects
json_value(object_t&& value)
{
object = create(std::move(value));
}
/// constructor for arrays
json_value(const array_t& value)
{
array = create(value);
}
/// constructor for rvalue arrays
json_value(array_t&& value)
{
array = create(std::move(value));
}
void destroy(value_t t) noexcept
{
switch (t)
{
case value_t::object:
{
AllocatorType alloc;
std::allocator_traits::destroy(alloc, object);
std::allocator_traits::deallocate(alloc, object, 1);
break;
}
case value_t::array:
{
AllocatorType alloc;
std::allocator_traits::destroy(alloc, array);
std::allocator_traits::deallocate(alloc, array, 1);
break;
}
case value_t::string:
{
AllocatorType alloc;
std::allocator_traits::destroy(alloc, string);
std::allocator_traits::deallocate(alloc, string, 1);
break;
}
default:
{
break;
}
}
}
};
/*!
@brief checks the class invariants
This function asserts the class invariants. It needs to be called at the
end of every constructor to make sure that created objects respect the
invariant. Furthermore, it has to be called each time the type of a JSON
value is changed, because the invariant expresses a relationship between
@a m_type and @a m_value.
*/
void assert_invariant() const noexcept
{
assert(m_type != value_t::object or m_value.object != nullptr);
assert(m_type != value_t::array or m_value.array != nullptr);
assert(m_type != value_t::string or m_value.string != nullptr);
}
public:
//////////////////////////
// JSON parser callback //
//////////////////////////
/*!
@brief parser event types
The parser callback distinguishes the following events:
– `object_start`: the parser read `{` and started to process a JSON object
– `key`: the parser read a key of a value in an object
– `object_end`: the parser read `}` and finished processing a JSON object
– `array_start`: the parser read `[` and started to process a JSON array
– `array_end`: the parser read `]` and finished processing a JSON array
– `value`: the parser finished reading a JSON value
@image html callback_events.png “Example when certain parse events are triggered”
@sa @ref parser_callback_t for more information and examples
*/
using parse_event_t = typename parser::parse_event_t;
/*!
@brief per-element parser callback type
With a parser callback function, the result of parsing a JSON text can be
influenced. When passed to @ref parse, it is called on certain events
(passed as @ref parse_event_t via parameter @a event) with a set recursion
depth @a depth and context JSON value @a parsed. The return value of the
callback function is a boolean indicating whether the element that emitted
the callback shall be kept or not.
We distinguish six scenarios (determined by the event type) in which the
callback function can be called. The following table describes the values
of the parameters @a depth, @a event, and @a parsed.
parameter @a event | description | parameter @a depth | parameter @a parsed
—————— | ———– | —————— | ——————-
parse_event_t::object_start | the parser read `{` and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded
parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key
parse_event_t::object_end | the parser read `}` and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object
parse_event_t::array_start | the parser read `[` and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded
parse_event_t::array_end | the parser read `]` and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array
parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value
@image html callback_events.png “Example when certain parse events are triggered”
Discarding a value (i.e., returning `false`) has different effects
depending on the context in which function was called:
– Discarded values in structured types are skipped. That is, the parser
will behave as if the discarded value was never read.
– In case a value outside a structured type is skipped, it is replaced
with `null`. This case happens if the top-level element is skipped.
@param[in] depth the depth of the recursion during parsing
@param[in] event an event of type parse_event_t indicating the context in
the callback function has been called
@param[in,out] parsed the current intermediate parse result; note that
writing to this value has no effect for parse_event_t::key events
@return Whether the JSON value which called the function during parsing
should be kept (`true`) or not (`false`). In the latter case, it is either
skipped completely or replaced by an empty discarded object.
@sa @ref parse for examples
@since version 1.0.0
*/
using parser_callback_t = typename parser::parser_callback_t;
//////////////////
// constructors //
//////////////////
/// @name constructors and destructors
/// Constructors of class @ref basic_json, copy/move constructor, copy
/// assignment, static functions creating objects, and the destructor.
/// @{
/*!
@brief create an empty value with a given type
Create an empty JSON value with a given type. The value will be default
initialized with an empty value which depends on the type:
Value type | initial value
———– | ————-
null | `null`
boolean | `false`
string | `””`
number | `0`
object | `{}`
array | `[]`
@param[in] v the type of the value to create
@complexity Constant.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes to any JSON value.
@liveexample{The following code shows the constructor for different @ref
value_t values,basic_json__value_t}
@sa @ref clear() — restores the postcondition of this constructor
@since version 1.0.0
*/
basic_json(const value_t v)
: m_type(v), m_value(v)
{
assert_invariant();
}
/*!
@brief create a null object
Create a `null` JSON value. It either takes a null pointer as parameter
(explicitly creating `null`) or no parameter (implicitly creating `null`).
The passed null pointer itself is not read — it is only used to choose
the right constructor.
@complexity Constant.
@exceptionsafety No-throw guarantee: this constructor never throws
exceptions.
@liveexample{The following code shows the constructor with and without a
null pointer parameter.,basic_json__nullptr_t}
@since version 1.0.0
*/
basic_json(std::nullptr_t = nullptr) noexcept
: basic_json(value_t::null)
{
assert_invariant();
}
/*!
@brief create a JSON value
This is a “catch all” constructor for all compatible JSON types; that is,
types for which a `to_json()` method exists. The constructor forwards the
parameter @a val to that method (to `json_serializer::to_json` method
with `U = uncvref_t`, to be exact).
Template type @a CompatibleType includes, but is not limited to, the
following types:
– **arrays**: @ref array_t and all kinds of compatible containers such as
`std::vector`, `std::deque`, `std::list`, `std::forward_list`,
`std::array`, `std::valarray`, `std::set`, `std::unordered_set`,
`std::multiset`, and `std::unordered_multiset` with a `value_type` from
which a @ref basic_json value can be constructed.
– **objects**: @ref object_t and all kinds of compatible associative
containers such as `std::map`, `std::unordered_map`, `std::multimap`,
and `std::unordered_multimap` with a `key_type` compatible to
@ref string_t and a `value_type` from which a @ref basic_json value can
be constructed.
– **strings**: @ref string_t, string literals, and all compatible string
containers can be used.
– **numbers**: @ref number_integer_t, @ref number_unsigned_t,
@ref number_float_t, and all convertible number types such as `int`,
`size_t`, `int64_t`, `float` or `double` can be used.
– **boolean**: @ref boolean_t / `bool` can be used.
See the examples below.
@tparam CompatibleType a type such that:
– @a CompatibleType is not derived from `std::istream`,
– @a CompatibleType is not @ref basic_json (to avoid hijacking copy/move
constructors),
– @a CompatibleType is not a different @ref basic_json type (i.e. with different template arguments)
– @a CompatibleType is not a @ref basic_json nested type (e.g.,
@ref json_pointer, @ref iterator, etc …)
– @ref @ref json_serializer has a
`to_json(basic_json_t&, CompatibleType&&)` method
@tparam U = `uncvref_t`
@param[in] val the value to be forwarded to the respective constructor
@complexity Usually linear in the size of the passed @a val, also
depending on the implementation of the called `to_json()`
method.
@exceptionsafety Depends on the called constructor. For types directly
supported by the library (i.e., all types for which no `to_json()` function
was provided), strong guarantee holds: if an exception is thrown, there are
no changes to any JSON value.
@liveexample{The following code shows the constructor with several
compatible types.,basic_json__CompatibleType}
@since version 2.1.0
*/
template ,
detail::enable_if_t<
not detail::is_basic_json::value and detail::is_compatible_type::value, int> = 0>
basic_json(CompatibleType && val) noexcept(noexcept(
JSONSerializer::to_json(std::declval(),
std::forward(val))))
{
JSONSerializer::to_json(*this, std::forward(val));
assert_invariant();
}
/*!
@brief create a JSON value from an existing one
This is a constructor for existing @ref basic_json types.
It does not hijack copy/move constructors, since the parameter has different
template arguments than the current ones.
The constructor tries to convert the internal @ref m_value of the parameter.
@tparam BasicJsonType a type such that:
– @a BasicJsonType is a @ref basic_json type.
– @a BasicJsonType has different template arguments than @ref basic_json_t.
@param[in] val the @ref basic_json value to be converted.
@complexity Usually linear in the size of the passed @a val, also
depending on the implementation of the called `to_json()`
method.
@exceptionsafety Depends on the called constructor. For types directly
supported by the library (i.e., all types for which no `to_json()` function
was provided), strong guarantee holds: if an exception is thrown, there are
no changes to any JSON value.
@since version 3.2.0
*/
template ::value and not std::is_same::value, int> = 0>
basic_json(const BasicJsonType& val)
{
using other_boolean_t = typename BasicJsonType::boolean_t;
using other_number_float_t = typename BasicJsonType::number_float_t;
using other_number_integer_t = typename BasicJsonType::number_integer_t;
using other_number_unsigned_t = typename BasicJsonType::number_unsigned_t;
using other_string_t = typename BasicJsonType::string_t;
using other_object_t = typename BasicJsonType::object_t;
using other_array_t = typename BasicJsonType::array_t;
switch (val.type())
{
case value_t::boolean:
JSONSerializer::to_json(*this, val.template get());
break;
case value_t::number_float:
JSONSerializer::to_json(*this, val.template get());
break;
case value_t::number_integer:
JSONSerializer::to_json(*this, val.template get());
break;
case value_t::number_unsigned:
JSONSerializer::to_json(*this, val.template get());
break;
case value_t::string:
JSONSerializer::to_json(*this, val.template get_ref());
break;
case value_t::object:
JSONSerializer::to_json(*this, val.template get_ref());
break;
case value_t::array:
JSONSerializer::to_json(*this, val.template get_ref());
break;
case value_t::null:
*this = nullptr;
break;
case value_t::discarded:
m_type = value_t::discarded;
break;
}
assert_invariant();
}
/*!
@brief create a container (array or object) from an initializer list
Creates a JSON value of type array or object from the passed initializer
list @a init. In case @a type_deduction is `true` (default), the type of
the JSON value to be created is deducted from the initializer list @a init
according to the following rules:
1. If the list is empty, an empty JSON object value `{}` is created.
2. If the list consists of pairs whose first element is a string, a JSON
object value is created where the first elements of the pairs are
treated as keys and the second elements are as values.
3. In all other cases, an array is created.
The rules aim to create the best fit between a C++ initializer list and
JSON values. The rationale is as follows:
1. The empty initializer list is written as `{}` which is exactly an empty
JSON object.
2. C++ has no way of describing mapped types other than to list a list of
pairs. As JSON requires that keys must be of type string, rule 2 is the
weakest constraint one can pose on initializer lists to interpret them
as an object.
3. In all other cases, the initializer list could not be interpreted as
JSON object type, so interpreting it as JSON array type is safe.
With the rules described above, the following JSON values cannot be
expressed by an initializer list:
– the empty array (`[]`): use @ref array(initializer_list_t)
with an empty initializer list in this case
– arrays whose elements satisfy rule 2: use @ref
array(initializer_list_t) with the same initializer list
in this case
@note When used without parentheses around an empty initializer list, @ref
basic_json() is called instead of this function, yielding the JSON null
value.
@param[in] init initializer list with JSON values
@param[in] type_deduction internal parameter; when set to `true`, the type
of the JSON value is deducted from the initializer list @a init; when set
to `false`, the type provided via @a manual_type is forced. This mode is
used by the functions @ref array(initializer_list_t) and
@ref object(initializer_list_t).
@param[in] manual_type internal parameter; when @a type_deduction is set
to `false`, the created JSON value will use the provided type (only @ref
value_t::array and @ref value_t::object are valid); when @a type_deduction
is set to `true`, this parameter has no effect
@throw type_error.301 if @a type_deduction is `false`, @a manual_type is
`value_t::object`, but @a init contains an element which is not a pair
whose first element is a string. In this case, the constructor could not
create an object. If @a type_deduction would have be `true`, an array
would have been created. See @ref object(initializer_list_t)
for an example.
@complexity Linear in the size of the initializer list @a init.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes to any JSON value.
@liveexample{The example below shows how JSON values are created from
initializer lists.,basic_json__list_init_t}
@sa @ref array(initializer_list_t) — create a JSON array
value from an initializer list
@sa @ref object(initializer_list_t) — create a JSON object
value from an initializer list
@since version 1.0.0
*/
basic_json(initializer_list_t init,
bool type_deduction = true,
value_t manual_type = value_t::array)
{
// check if each element is an array with two elements whose first
// element is a string
bool is_an_object = std::all_of(init.begin(), init.end(),
[](const detail::json_ref& element_ref)
{
return (element_ref->is_array() and element_ref->size() == 2 and (*element_ref)[0].is_string());
});
// adjust type if type deduction is not wanted
if (not type_deduction)
{
// if array is wanted, do not create an object though possible
if (manual_type == value_t::array)
{
is_an_object = false;
}
// if object is wanted but impossible, throw an exception
if (JSON_UNLIKELY(manual_type == value_t::object and not is_an_object))
{
JSON_THROW(type_error::create(301, “cannot create object from initializer list”));
}
}
if (is_an_object)
{
// the initializer list is a list of pairs -> create object
m_type = value_t::object;
m_value = value_t::object;
std::for_each(init.begin(), init.end(), [this](const detail::json_ref& element_ref)
{
auto element = element_ref.moved_or_copied();
m_value.object->emplace(
std::move(*((*element.m_value.array)[0].m_value.string)),
std::move((*element.m_value.array)[1]));
});
}
else
{
// the initializer list describes an array -> create array
m_type = value_t::array;
m_value.array = create(init.begin(), init.end());
}
assert_invariant();
}
/*!
@brief explicitly create an array from an initializer list
Creates a JSON array value from a given initializer list. That is, given a
list of values `a, b, c`, creates the JSON value `[a, b, c]`. If the
initializer list is empty, the empty array `[]` is created.
@note This function is only needed to express two edge cases that cannot
be realized with the initializer list constructor (@ref
basic_json(initializer_list_t, bool, value_t)). These cases
are:
1. creating an array whose elements are all pairs whose first element is a
string — in this case, the initializer list constructor would create an
object, taking the first elements as keys
2. creating an empty array — passing the empty initializer list to the
initializer list constructor yields an empty object
@param[in] init initializer list with JSON values to create an array from
(optional)
@return JSON array value
@complexity Linear in the size of @a init.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes to any JSON value.
@liveexample{The following code shows an example for the `array`
function.,array}
@sa @ref basic_json(initializer_list_t, bool, value_t) —
create a JSON value from an initializer list
@sa @ref object(initializer_list_t) — create a JSON object
value from an initializer list
@since version 1.0.0
*/
JSON_NODISCARD
static basic_json array(initializer_list_t init = {})
{
return basic_json(init, false, value_t::array);
}
/*!
@brief explicitly create an object from an initializer list
Creates a JSON object value from a given initializer list. The initializer
lists elements must be pairs, and their first elements must be strings. If
the initializer list is empty, the empty object `{}` is created.
@note This function is only added for symmetry reasons. In contrast to the
related function @ref array(initializer_list_t), there are
no cases which can only be expressed by this function. That is, any
initializer list @a init can also be passed to the initializer list
constructor @ref basic_json(initializer_list_t, bool, value_t).
@param[in] init initializer list to create an object from (optional)
@return JSON object value
@throw type_error.301 if @a init is not a list of pairs whose first
elements are strings. In this case, no object can be created. When such a
value is passed to @ref basic_json(initializer_list_t, bool, value_t),
an array would have been created from the passed initializer list @a init.
See example below.
@complexity Linear in the size of @a init.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes to any JSON value.
@liveexample{The following code shows an example for the `object`
function.,object}
@sa @ref basic_json(initializer_list_t, bool, value_t) —
create a JSON value from an initializer list
@sa @ref array(initializer_list_t) — create a JSON array
value from an initializer list
@since version 1.0.0
*/
JSON_NODISCARD
static basic_json object(initializer_list_t init = {})
{
return basic_json(init, false, value_t::object);
}
/*!
@brief construct an array with count copies of given value
Constructs a JSON array value by creating @a cnt copies of a passed value.
In case @a cnt is `0`, an empty array is created.
@param[in] cnt the number of JSON copies of @a val to create
@param[in] val the JSON value to copy
@post `std::distance(begin(),end()) == cnt` holds.
@complexity Linear in @a cnt.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes to any JSON value.
@liveexample{The following code shows examples for the @ref
basic_json(size_type\, const basic_json&)
constructor.,basic_json__size_type_basic_json}
@since version 1.0.0
*/
basic_json(size_type cnt, const basic_json& val)
: m_type(value_t::array)
{
m_value.array = create(cnt, val);
assert_invariant();
}
/*!
@brief construct a JSON container given an iterator range
Constructs the JSON value with the contents of the range `[first, last)`.
The semantics depends on the different types a JSON value can have:
– In case of a null type, invalid_iterator.206 is thrown.
– In case of other primitive types (number, boolean, or string), @a first
must be `begin()` and @a last must be `end()`. In this case, the value is
copied. Otherwise, invalid_iterator.204 is thrown.
– In case of structured types (array, object), the constructor behaves as
similar versions for `std::vector` or `std::map`; that is, a JSON array
or object is constructed from the values in the range.
@tparam InputIT an input iterator type (@ref iterator or @ref
const_iterator)
@param[in] first begin of the range to copy from (included)
@param[in] last end of the range to copy from (excluded)
@pre Iterators @a first and @a last must be initialized. **This
precondition is enforced with an assertion (see warning).** If
assertions are switched off, a violation of this precondition yields
undefined behavior.
@pre Range `[first, last)` is valid. Usually, this precondition cannot be
checked efficiently. Only certain edge cases are detected; see the
description of the exceptions below. A violation of this precondition
yields undefined behavior.
@warning A precondition is enforced with a runtime assertion that will
result in calling `std::abort` if this precondition is not met.
Assertions can be disabled by defining `NDEBUG` at compile time.
See https://en.cppreference.com/w/cpp/error/assert for more
information.
@throw invalid_iterator.201 if iterators @a first and @a last are not
compatible (i.e., do not belong to the same JSON value). In this case,
the range `[first, last)` is undefined.
@throw invalid_iterator.204 if iterators @a first and @a last belong to a
primitive type (number, boolean, or string), but @a first does not point
to the first element any more. In this case, the range `[first, last)` is
undefined. See example code below.
@throw invalid_iterator.206 if iterators @a first and @a last belong to a
null value. In this case, the range `[first, last)` is undefined.
@complexity Linear in distance between @a first and @a last.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes to any JSON value.
@liveexample{The example below shows several ways to create JSON values by
specifying a subrange with iterators.,basic_json__InputIt_InputIt}
@since version 1.0.0
*/
template::value or
std::is_same::value, int>::type = 0>
basic_json(InputIT first, InputIT last)
{
assert(first.m_object != nullptr);
assert(last.m_object != nullptr);
// make sure iterator fits the current value
if (JSON_UNLIKELY(first.m_object != last.m_object))
{
JSON_THROW(invalid_iterator::create(201, “iterators are not compatible”));
}
// copy type from first iterator
m_type = first.m_object->m_type;
// check if iterator range is complete for primitive values
switch (m_type)
{
case value_t::boolean:
case value_t::number_float:
case value_t::number_integer:
case value_t::number_unsigned:
case value_t::string:
{
if (JSON_UNLIKELY(not first.m_it.primitive_iterator.is_begin()
or not last.m_it.primitive_iterator.is_end()))
{
JSON_THROW(invalid_iterator::create(204, “iterators out of range”));
}
break;
}
default:
break;
}
switch (m_type)
{
case value_t::number_integer:
{
m_value.number_integer = first.m_object->m_value.number_integer;
break;
}
case value_t::number_unsigned:
{
m_value.number_unsigned = first.m_object->m_value.number_unsigned;
break;
}
case value_t::number_float:
{
m_value.number_float = first.m_object->m_value.number_float;
break;
}
case value_t::boolean:
{
m_value.boolean = first.m_object->m_value.boolean;
break;
}
case value_t::string:
{
m_value = *first.m_object->m_value.string;
break;
}
case value_t::object:
{
m_value.object = create(first.m_it.object_iterator,
last.m_it.object_iterator);
break;
}
case value_t::array:
{
m_value.array = create(first.m_it.array_iterator,
last.m_it.array_iterator);
break;
}
default:
JSON_THROW(invalid_iterator::create(206, “cannot construct with iterators from ” +
std::string(first.m_object->type_name())));
}
assert_invariant();
}
///////////////////////////////////////
// other constructors and destructor //
///////////////////////////////////////
/// @private
basic_json(const detail::json_ref& ref)
: basic_json(ref.moved_or_copied())
{}
/*!
@brief copy constructor
Creates a copy of a given JSON value.
@param[in] other the JSON value to copy
@post `*this == other`
@complexity Linear in the size of @a other.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes to any JSON value.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is linear.
– As postcondition, it holds: `other == basic_json(other)`.
@liveexample{The following code shows an example for the copy
constructor.,basic_json__basic_json}
@since version 1.0.0
*/
basic_json(const basic_json& other)
: m_type(other.m_type)
{
// check of passed value is valid
other.assert_invariant();
switch (m_type)
{
case value_t::object:
{
m_value = *other.m_value.object;
break;
}
case value_t::array:
{
m_value = *other.m_value.array;
break;
}
case value_t::string:
{
m_value = *other.m_value.string;
break;
}
case value_t::boolean:
{
m_value = other.m_value.boolean;
break;
}
case value_t::number_integer:
{
m_value = other.m_value.number_integer;
break;
}
case value_t::number_unsigned:
{
m_value = other.m_value.number_unsigned;
break;
}
case value_t::number_float:
{
m_value = other.m_value.number_float;
break;
}
default:
break;
}
assert_invariant();
}
/*!
@brief move constructor
Move constructor. Constructs a JSON value with the contents of the given
value @a other using move semantics. It “steals” the resources from @a
other and leaves it as JSON null value.
@param[in,out] other value to move to this object
@post `*this` has the same value as @a other before the call.
@post @a other is a JSON null value.
@complexity Constant.
@exceptionsafety No-throw guarantee: this constructor never throws
exceptions.
@requirement This function helps `basic_json` satisfying the
[MoveConstructible](https://en.cppreference.com/w/cpp/named_req/MoveConstructible)
requirements.
@liveexample{The code below shows the move constructor explicitly called
via std::move.,basic_json__moveconstructor}
@since version 1.0.0
*/
basic_json(basic_json&& other) noexcept
: m_type(std::move(other.m_type)),
m_value(std::move(other.m_value))
{
// check that passed value is valid
other.assert_invariant();
// invalidate payload
other.m_type = value_t::null;
other.m_value = {};
assert_invariant();
}
/*!
@brief copy assignment
Copy assignment operator. Copies a JSON value via the “copy and swap”
strategy: It is expressed in terms of the copy constructor, destructor,
and the `swap()` member function.
@param[in] other value to copy from
@complexity Linear.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is linear.
@liveexample{The code below shows and example for the copy assignment. It
creates a copy of value `a` which is then swapped with `b`. Finally\, the
copy of `a` (which is the null value after the swap) is
destroyed.,basic_json__copyassignment}
@since version 1.0.0
*/
basic_json& operator=(basic_json other) noexcept (
std::is_nothrow_move_constructible::value and
std::is_nothrow_move_assignable::value and
std::is_nothrow_move_constructible::value and
std::is_nothrow_move_assignable::value
)
{
// check that passed value is valid
other.assert_invariant();
using std::swap;
swap(m_type, other.m_type);
swap(m_value, other.m_value);
assert_invariant();
return *this;
}
/*!
@brief destructor
Destroys the JSON value and frees all allocated memory.
@complexity Linear.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is linear.
– All stored elements are destroyed and all memory is freed.
@since version 1.0.0
*/
~basic_json() noexcept
{
assert_invariant();
m_value.destroy(m_type);
}
/// @}
public:
///////////////////////
// object inspection //
///////////////////////
/// @name object inspection
/// Functions to inspect the type of a JSON value.
/// @{
/*!
@brief serialization
Serialization function for JSON values. The function tries to mimic
Python’s `json.dumps()` function, and currently supports its @a indent
and @a ensure_ascii parameters.
@param[in] indent If indent is nonnegative, then array elements and object
members will be pretty-printed with that indent level. An indent level of
`0` will only insert newlines. `-1` (the default) selects the most compact
representation.
@param[in] indent_char The character to use for indentation if @a indent is
greater than `0`. The default is ` ` (space).
@param[in] ensure_ascii If @a ensure_ascii is true, all non-ASCII characters
in the output are escaped with `\uXXXX` sequences, and the result consists
of ASCII characters only.
@param[in] error_handler how to react on decoding errors; there are three
possible values: `strict` (throws and exception in case a decoding error
occurs; default), `replace` (replace invalid UTF-8 sequences with U+FFFD),
and `ignore` (ignore invalid UTF-8 sequences during serialization).
@return string containing the serialization of the JSON value
@throw type_error.316 if a string stored inside the JSON value is not
UTF-8 encoded
@complexity Linear.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes in the JSON value.
@liveexample{The following example shows the effect of different @a indent\,
@a indent_char\, and @a ensure_ascii parameters to the result of the
serialization.,dump}
@see https://docs.python.org/2/library/json.html#json.dump
@since version 1.0.0; indentation character @a indent_char, option
@a ensure_ascii and exceptions added in version 3.0.0; error
handlers added in version 3.4.0.
*/
string_t dump(const int indent = -1,
const char indent_char = ‘ ‘,
const bool ensure_ascii = false,
const error_handler_t error_handler = error_handler_t::strict) const
{
string_t result;
serializer s(detail::output_adapter(result), indent_char, error_handler);
if (indent >= 0)
{
s.dump(*this, true, ensure_ascii, static_cast(indent));
}
else
{
s.dump(*this, false, ensure_ascii, 0);
}
return result;
}
/*!
@brief return the type of the JSON value (explicit)
Return the type of the JSON value as a value from the @ref value_t
enumeration.
@return the type of the JSON value
Value type | return value
————————- | ————————-
null | value_t::null
boolean | value_t::boolean
string | value_t::string
number (integer) | value_t::number_integer
number (unsigned integer) | value_t::number_unsigned
number (floating-point) | value_t::number_float
object | value_t::object
array | value_t::array
discarded | value_t::discarded
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `type()` for all JSON
types.,type}
@sa @ref operator value_t() — return the type of the JSON value (implicit)
@sa @ref type_name() — return the type as string
@since version 1.0.0
*/
constexpr value_t type() const noexcept
{
return m_type;
}
/*!
@brief return whether type is primitive
This function returns true if and only if the JSON type is primitive
(string, number, boolean, or null).
@return `true` if type is primitive (string, number, boolean, or null),
`false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_primitive()` for all JSON
types.,is_primitive}
@sa @ref is_structured() — returns whether JSON value is structured
@sa @ref is_null() — returns whether JSON value is `null`
@sa @ref is_string() — returns whether JSON value is a string
@sa @ref is_boolean() — returns whether JSON value is a boolean
@sa @ref is_number() — returns whether JSON value is a number
@since version 1.0.0
*/
constexpr bool is_primitive() const noexcept
{
return is_null() or is_string() or is_boolean() or is_number();
}
/*!
@brief return whether type is structured
This function returns true if and only if the JSON type is structured
(array or object).
@return `true` if type is structured (array or object), `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_structured()` for all JSON
types.,is_structured}
@sa @ref is_primitive() — returns whether value is primitive
@sa @ref is_array() — returns whether value is an array
@sa @ref is_object() — returns whether value is an object
@since version 1.0.0
*/
constexpr bool is_structured() const noexcept
{
return is_array() or is_object();
}
/*!
@brief return whether value is null
This function returns true if and only if the JSON value is null.
@return `true` if type is null, `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_null()` for all JSON
types.,is_null}
@since version 1.0.0
*/
constexpr bool is_null() const noexcept
{
return (m_type == value_t::null);
}
/*!
@brief return whether value is a boolean
This function returns true if and only if the JSON value is a boolean.
@return `true` if type is boolean, `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_boolean()` for all JSON
types.,is_boolean}
@since version 1.0.0
*/
constexpr bool is_boolean() const noexcept
{
return (m_type == value_t::boolean);
}
/*!
@brief return whether value is a number
This function returns true if and only if the JSON value is a number. This
includes both integer (signed and unsigned) and floating-point values.
@return `true` if type is number (regardless whether integer, unsigned
integer or floating-type), `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_number()` for all JSON
types.,is_number}
@sa @ref is_number_integer() — check if value is an integer or unsigned
integer number
@sa @ref is_number_unsigned() — check if value is an unsigned integer
number
@sa @ref is_number_float() — check if value is a floating-point number
@since version 1.0.0
*/
constexpr bool is_number() const noexcept
{
return is_number_integer() or is_number_float();
}
/*!
@brief return whether value is an integer number
This function returns true if and only if the JSON value is a signed or
unsigned integer number. This excludes floating-point values.
@return `true` if type is an integer or unsigned integer number, `false`
otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_number_integer()` for all
JSON types.,is_number_integer}
@sa @ref is_number() — check if value is a number
@sa @ref is_number_unsigned() — check if value is an unsigned integer
number
@sa @ref is_number_float() — check if value is a floating-point number
@since version 1.0.0
*/
constexpr bool is_number_integer() const noexcept
{
return (m_type == value_t::number_integer or m_type == value_t::number_unsigned);
}
/*!
@brief return whether value is an unsigned integer number
This function returns true if and only if the JSON value is an unsigned
integer number. This excludes floating-point and signed integer values.
@return `true` if type is an unsigned integer number, `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_number_unsigned()` for all
JSON types.,is_number_unsigned}
@sa @ref is_number() — check if value is a number
@sa @ref is_number_integer() — check if value is an integer or unsigned
integer number
@sa @ref is_number_float() — check if value is a floating-point number
@since version 2.0.0
*/
constexpr bool is_number_unsigned() const noexcept
{
return (m_type == value_t::number_unsigned);
}
/*!
@brief return whether value is a floating-point number
This function returns true if and only if the JSON value is a
floating-point number. This excludes signed and unsigned integer values.
@return `true` if type is a floating-point number, `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_number_float()` for all
JSON types.,is_number_float}
@sa @ref is_number() — check if value is number
@sa @ref is_number_integer() — check if value is an integer number
@sa @ref is_number_unsigned() — check if value is an unsigned integer
number
@since version 1.0.0
*/
constexpr bool is_number_float() const noexcept
{
return (m_type == value_t::number_float);
}
/*!
@brief return whether value is an object
This function returns true if and only if the JSON value is an object.
@return `true` if type is object, `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_object()` for all JSON
types.,is_object}
@since version 1.0.0
*/
constexpr bool is_object() const noexcept
{
return (m_type == value_t::object);
}
/*!
@brief return whether value is an array
This function returns true if and only if the JSON value is an array.
@return `true` if type is array, `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_array()` for all JSON
types.,is_array}
@since version 1.0.0
*/
constexpr bool is_array() const noexcept
{
return (m_type == value_t::array);
}
/*!
@brief return whether value is a string
This function returns true if and only if the JSON value is a string.
@return `true` if type is string, `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_string()` for all JSON
types.,is_string}
@since version 1.0.0
*/
constexpr bool is_string() const noexcept
{
return (m_type == value_t::string);
}
/*!
@brief return whether value is discarded
This function returns true if and only if the JSON value was discarded
during parsing with a callback function (see @ref parser_callback_t).
@note This function will always be `false` for JSON values after parsing.
That is, discarded values can only occur during parsing, but will be
removed when inside a structured value or replaced by null in other cases.
@return `true` if type is discarded, `false` otherwise.
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies `is_discarded()` for all JSON
types.,is_discarded}
@since version 1.0.0
*/
constexpr bool is_discarded() const noexcept
{
return (m_type == value_t::discarded);
}
/*!
@brief return the type of the JSON value (implicit)
Implicitly return the type of the JSON value as a value from the @ref
value_t enumeration.
@return the type of the JSON value
@complexity Constant.
@exceptionsafety No-throw guarantee: this member function never throws
exceptions.
@liveexample{The following code exemplifies the @ref value_t operator for
all JSON types.,operator__value_t}
@sa @ref type() — return the type of the JSON value (explicit)
@sa @ref type_name() — return the type as string
@since version 1.0.0
*/
constexpr operator value_t() const noexcept
{
return m_type;
}
/// @}
private:
//////////////////
// value access //
//////////////////
/// get a boolean (explicit)
boolean_t get_impl(boolean_t* /*unused*/) const
{
if (JSON_LIKELY(is_boolean()))
{
return m_value.boolean;
}
JSON_THROW(type_error::create(302, “type must be boolean, but is ” + std::string(type_name())));
}
/// get a pointer to the value (object)
object_t* get_impl_ptr(object_t* /*unused*/) noexcept
{
return is_object() ? m_value.object : nullptr;
}
/// get a pointer to the value (object)
constexpr const object_t* get_impl_ptr(const object_t* /*unused*/) const noexcept
{
return is_object() ? m_value.object : nullptr;
}
/// get a pointer to the value (array)
array_t* get_impl_ptr(array_t* /*unused*/) noexcept
{
return is_array() ? m_value.array : nullptr;
}
/// get a pointer to the value (array)
constexpr const array_t* get_impl_ptr(const array_t* /*unused*/) const noexcept
{
return is_array() ? m_value.array : nullptr;
}
/// get a pointer to the value (string)
string_t* get_impl_ptr(string_t* /*unused*/) noexcept
{
return is_string() ? m_value.string : nullptr;
}
/// get a pointer to the value (string)
constexpr const string_t* get_impl_ptr(const string_t* /*unused*/) const noexcept
{
return is_string() ? m_value.string : nullptr;
}
/// get a pointer to the value (boolean)
boolean_t* get_impl_ptr(boolean_t* /*unused*/) noexcept
{
return is_boolean() ? &m_value.boolean : nullptr;
}
/// get a pointer to the value (boolean)
constexpr const boolean_t* get_impl_ptr(const boolean_t* /*unused*/) const noexcept
{
return is_boolean() ? &m_value.boolean : nullptr;
}
/// get a pointer to the value (integer number)
number_integer_t* get_impl_ptr(number_integer_t* /*unused*/) noexcept
{
return is_number_integer() ? &m_value.number_integer : nullptr;
}
/// get a pointer to the value (integer number)
constexpr const number_integer_t* get_impl_ptr(const number_integer_t* /*unused*/) const noexcept
{
return is_number_integer() ? &m_value.number_integer : nullptr;
}
/// get a pointer to the value (unsigned number)
number_unsigned_t* get_impl_ptr(number_unsigned_t* /*unused*/) noexcept
{
return is_number_unsigned() ? &m_value.number_unsigned : nullptr;
}
/// get a pointer to the value (unsigned number)
constexpr const number_unsigned_t* get_impl_ptr(const number_unsigned_t* /*unused*/) const noexcept
{
return is_number_unsigned() ? &m_value.number_unsigned : nullptr;
}
/// get a pointer to the value (floating-point number)
number_float_t* get_impl_ptr(number_float_t* /*unused*/) noexcept
{
return is_number_float() ? &m_value.number_float : nullptr;
}
/// get a pointer to the value (floating-point number)
constexpr const number_float_t* get_impl_ptr(const number_float_t* /*unused*/) const noexcept
{
return is_number_float() ? &m_value.number_float : nullptr;
}
/*!
@brief helper function to implement get_ref()
This function helps to implement get_ref() without code duplication for
const and non-const overloads
@tparam ThisType will be deduced as `basic_json` or `const basic_json`
@throw type_error.303 if ReferenceType does not match underlying value
type of the current JSON
*/
template
static ReferenceType get_ref_impl(ThisType& obj)
{
// delegate the call to get_ptr<>()
auto ptr = obj.template get_ptr::type>();
if (JSON_LIKELY(ptr != nullptr))
{
return *ptr;
}
JSON_THROW(type_error::create(303, “incompatible ReferenceType for get_ref, actual type is ” + std::string(obj.type_name())));
}
public:
/// @name value access
/// Direct access to the stored value of a JSON value.
/// @{
/*!
@brief get special-case overload
This overloads avoids a lot of template boilerplate, it can be seen as the
identity method
@tparam BasicJsonType == @ref basic_json
@return a copy of *this
@complexity Constant.
@since version 2.1.0
*/
template::type, basic_json_t>::value,
int> = 0>
basic_json get() const
{
return *this;
}
/*!
@brief get special-case overload
This overloads converts the current @ref basic_json in a different
@ref basic_json type
@tparam BasicJsonType == @ref basic_json
@return a copy of *this, converted into @tparam BasicJsonType
@complexity Depending on the implementation of the called `from_json()`
method.
@since version 3.2.0
*/
template::value and
detail::is_basic_json::value, int> = 0>
BasicJsonType get() const
{
return *this;
}
/*!
@brief get a value (explicit)
Explicit type conversion between the JSON value and a compatible value
which is [CopyConstructible](https://en.cppreference.com/w/cpp/named_req/CopyConstructible)
and [DefaultConstructible](https://en.cppreference.com/w/cpp/named_req/DefaultConstructible).
The value is converted by calling the @ref json_serializer
`from_json()` method.
The function is equivalent to executing
@code {.cpp}
ValueType ret;
JSONSerializer::from_json(*this, ret);
return ret;
@endcode
This overloads is chosen if:
– @a ValueType is not @ref basic_json,
– @ref json_serializer has a `from_json()` method of the form
`void from_json(const basic_json&, ValueType&)`, and
– @ref json_serializer does not have a `from_json()` method of
the form `ValueType from_json(const basic_json&)`
@tparam ValueTypeCV the provided value type
@tparam ValueType the returned value type
@return copy of the JSON value, converted to @a ValueType
@throw what @ref json_serializer `from_json()` method throws
@liveexample{The example below shows several conversions from JSON values
to other types. There a few things to note: (1) Floating-point numbers can
be converted to integers\, (2) A JSON array can be converted to a standard
`std::vector`\, (3) A JSON object can be converted to C++
associative containers such as `std::unordered_map`.,get__ValueType_const}
@since version 2.1.0
*/
template,
detail::enable_if_t <
not detail::is_basic_json::value and
detail::has_from_json::value and
not detail::has_non_default_from_json::value,
int> = 0>
ValueType get() const noexcept(noexcept(
JSONSerializer::from_json(std::declval(), std::declval())))
{
// we cannot static_assert on ValueTypeCV being non-const, because
// there is support for get(), which is why we
// still need the uncvref
static_assert(not std::is_reference::value,
“get() cannot be used with reference types, you might want to use get_ref()”);
static_assert(std::is_default_constructible::value,
“types must be DefaultConstructible when used with get()”);
ValueType ret;
JSONSerializer::from_json(*this, ret);
return ret;
}
/*!
@brief get a value (explicit); special case
Explicit type conversion between the JSON value and a compatible value
which is **not** [CopyConstructible](https://en.cppreference.com/w/cpp/named_req/CopyConstructible)
and **not** [DefaultConstructible](https://en.cppreference.com/w/cpp/named_req/DefaultConstructible).
The value is converted by calling the @ref json_serializer
`from_json()` method.
The function is equivalent to executing
@code {.cpp}
return JSONSerializer::from_json(*this);
@endcode
This overloads is chosen if:
– @a ValueType is not @ref basic_json and
– @ref json_serializer has a `from_json()` method of the form
`ValueType from_json(const basic_json&)`
@note If @ref json_serializer has both overloads of
`from_json()`, this one is chosen.
@tparam ValueTypeCV the provided value type
@tparam ValueType the returned value type
@return copy of the JSON value, converted to @a ValueType
@throw what @ref json_serializer `from_json()` method throws
@since version 2.1.0
*/
template,
detail::enable_if_t::value and
detail::has_non_default_from_json::value,
int> = 0>
ValueType get() const noexcept(noexcept(
JSONSerializer::from_json(std::declval())))
{
static_assert(not std::is_reference::value,
“get() cannot be used with reference types, you might want to use get_ref()”);
return JSONSerializer::from_json(*this);
}
/*!
@brief get a value (explicit)
Explicit type conversion between the JSON value and a compatible value.
The value is filled into the input parameter by calling the @ref json_serializer
`from_json()` method.
The function is equivalent to executing
@code {.cpp}
ValueType v;
JSONSerializer::from_json(*this, v);
@endcode
This overloads is chosen if:
– @a ValueType is not @ref basic_json,
– @ref json_serializer has a `from_json()` method of the form
`void from_json(const basic_json&, ValueType&)`, and
@tparam ValueType the input parameter type.
@return the input parameter, allowing chaining calls.
@throw what @ref json_serializer `from_json()` method throws
@liveexample{The example below shows several conversions from JSON values
to other types. There a few things to note: (1) Floating-point numbers can
be converted to integers\, (2) A JSON array can be converted to a standard
`std::vector`\, (3) A JSON object can be converted to C++
associative containers such as `std::unordered_map`.,get_to}
@since version 3.3.0
*/
template::value and
detail::has_from_json::value,
int> = 0>
ValueType & get_to(ValueType& v) const noexcept(noexcept(
JSONSerializer::from_json(std::declval(), v)))
{
JSONSerializer::from_json(*this, v);
return v;
}
/*!
@brief get a pointer value (implicit)
Implicit pointer access to the internally stored JSON value. No copies are
made.
@warning Writing data to the pointee of the result yields an undefined
state.
@tparam PointerType pointer type; must be a pointer to @ref array_t, @ref
object_t, @ref string_t, @ref boolean_t, @ref number_integer_t,
@ref number_unsigned_t, or @ref number_float_t. Enforced by a static
assertion.
@return pointer to the internally stored JSON value if the requested
pointer type @a PointerType fits to the JSON value; `nullptr` otherwise
@complexity Constant.
@liveexample{The example below shows how pointers to internal values of a
JSON value can be requested. Note that no type conversions are made and a
`nullptr` is returned if the value and the requested pointer type does not
match.,get_ptr}
@since version 1.0.0
*/
template::value, int>::type = 0>
auto get_ptr() noexcept -> decltype(std::declval().get_impl_ptr(std::declval()))
{
// delegate the call to get_impl_ptr<>()
return get_impl_ptr(static_cast(nullptr));
}
/*!
@brief get a pointer value (implicit)
@copydoc get_ptr()
*/
template::value and
std::is_const::type>::value, int>::type = 0>
constexpr auto get_ptr() const noexcept -> decltype(std::declval().get_impl_ptr(std::declval()))
{
// delegate the call to get_impl_ptr<>() const
return get_impl_ptr(static_cast(nullptr));
}
/*!
@brief get a pointer value (explicit)
Explicit pointer access to the internally stored JSON value. No copies are
made.
@warning The pointer becomes invalid if the underlying JSON object
changes.
@tparam PointerType pointer type; must be a pointer to @ref array_t, @ref
object_t, @ref string_t, @ref boolean_t, @ref number_integer_t,
@ref number_unsigned_t, or @ref number_float_t.
@return pointer to the internally stored JSON value if the requested
pointer type @a PointerType fits to the JSON value; `nullptr` otherwise
@complexity Constant.
@liveexample{The example below shows how pointers to internal values of a
JSON value can be requested. Note that no type conversions are made and a
`nullptr` is returned if the value and the requested pointer type does not
match.,get__PointerType}
@sa @ref get_ptr() for explicit pointer-member access
@since version 1.0.0
*/
template::value, int>::type = 0>
auto get() noexcept -> decltype(std::declval().template get_ptr())
{
// delegate the call to get_ptr
return get_ptr();
}
/*!
@brief get a pointer value (explicit)
@copydoc get()
*/
template::value, int>::type = 0>
constexpr auto get() const noexcept -> decltype(std::declval().template get_ptr())
{
// delegate the call to get_ptr
return get_ptr();
}
/*!
@brief get a reference value (implicit)
Implicit reference access to the internally stored JSON value. No copies
are made.
@warning Writing data to the referee of the result yields an undefined
state.
@tparam ReferenceType reference type; must be a reference to @ref array_t,
@ref object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or
@ref number_float_t. Enforced by static assertion.
@return reference to the internally stored JSON value if the requested
reference type @a ReferenceType fits to the JSON value; throws
type_error.303 otherwise
@throw type_error.303 in case passed type @a ReferenceType is incompatible
with the stored JSON value; see example below
@complexity Constant.
@liveexample{The example shows several calls to `get_ref()`.,get_ref}
@since version 1.1.0
*/
template::value, int>::type = 0>
ReferenceType get_ref()
{
// delegate call to get_ref_impl
return get_ref_impl(*this);
}
/*!
@brief get a reference value (implicit)
@copydoc get_ref()
*/
template::value and
std::is_const::type>::value, int>::type = 0>
ReferenceType get_ref() const
{
// delegate call to get_ref_impl
return get_ref_impl(*this);
}
/*!
@brief get a value (implicit)
Implicit type conversion between the JSON value and a compatible value.
The call is realized by calling @ref get() const.
@tparam ValueType non-pointer type compatible to the JSON value, for
instance `int` for JSON integer numbers, `bool` for JSON booleans, or
`std::vector` types for JSON arrays. The character type of @ref string_t
as well as an initializer list of this type is excluded to avoid
ambiguities as these types implicitly convert to `std::string`.
@return copy of the JSON value, converted to type @a ValueType
@throw type_error.302 in case passed type @a ValueType is incompatible
to the JSON value type (e.g., the JSON value is of type boolean, but a
string is requested); see example below
@complexity Linear in the size of the JSON value.
@liveexample{The example below shows several conversions from JSON values
to other types. There a few things to note: (1) Floating-point numbers can
be converted to integers\, (2) A JSON array can be converted to a standard
`std::vector`\, (3) A JSON object can be converted to C++
associative containers such as `std::unordered_map`.,operator__ValueType}
@since version 1.0.0
*/
template < typename ValueType, typename std::enable_if <
not std::is_pointer::value and
not std::is_same>::value and
not std::is_same::value and
not detail::is_basic_json::value
#ifndef _MSC_VER // fix for issue #167 operator<< ambiguity under VS2015
and not std::is_same>::value
#if defined(JSON_HAS_CPP_17) && defined(_MSC_VER) and _MSC_VER <= 1914
and not std::is_same::value
#endif
#endif
and detail::is_detected::value
, int >::type = 0 >
operator ValueType() const
{
// delegate the call to get<>() const
return get();
}
/// @}
////////////////////
// element access //
////////////////////
/// @name element access
/// Access to the JSON value.
/// @{
/*!
@brief access specified array element with bounds checking
Returns a reference to the element at specified location @a idx, with
bounds checking.
@param[in] idx index of the element to access
@return reference to the element at index @a idx
@throw type_error.304 if the JSON value is not an array; in this case,
calling `at` with an index makes no sense. See example below.
@throw out_of_range.401 if the index @a idx is out of range of the array;
that is, `idx >= size()`. See example below.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes in the JSON value.
@complexity Constant.
@since version 1.0.0
@liveexample{The example below shows how array elements can be read and
written using `at()`. It also demonstrates the different exceptions that
can be thrown.,at__size_type}
*/
reference at(size_type idx)
{
// at only works for arrays
if (JSON_LIKELY(is_array()))
{
JSON_TRY
{
return m_value.array->at(idx);
}
JSON_CATCH (std::out_of_range&)
{
// create better exception explanation
JSON_THROW(out_of_range::create(401, “array index ” + std::to_string(idx) + ” is out of range”));
}
}
else
{
JSON_THROW(type_error::create(304, “cannot use at() with ” + std::string(type_name())));
}
}
/*!
@brief access specified array element with bounds checking
Returns a const reference to the element at specified location @a idx,
with bounds checking.
@param[in] idx index of the element to access
@return const reference to the element at index @a idx
@throw type_error.304 if the JSON value is not an array; in this case,
calling `at` with an index makes no sense. See example below.
@throw out_of_range.401 if the index @a idx is out of range of the array;
that is, `idx >= size()`. See example below.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes in the JSON value.
@complexity Constant.
@since version 1.0.0
@liveexample{The example below shows how array elements can be read using
`at()`. It also demonstrates the different exceptions that can be thrown.,
at__size_type_const}
*/
const_reference at(size_type idx) const
{
// at only works for arrays
if (JSON_LIKELY(is_array()))
{
JSON_TRY
{
return m_value.array->at(idx);
}
JSON_CATCH (std::out_of_range&)
{
// create better exception explanation
JSON_THROW(out_of_range::create(401, “array index ” + std::to_string(idx) + ” is out of range”));
}
}
else
{
JSON_THROW(type_error::create(304, “cannot use at() with ” + std::string(type_name())));
}
}
/*!
@brief access specified object element with bounds checking
Returns a reference to the element at with specified key @a key, with
bounds checking.
@param[in] key key of the element to access
@return reference to the element at key @a key
@throw type_error.304 if the JSON value is not an object; in this case,
calling `at` with a key makes no sense. See example below.
@throw out_of_range.403 if the key @a key is is not stored in the object;
that is, `find(key) == end()`. See example below.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes in the JSON value.
@complexity Logarithmic in the size of the container.
@sa @ref operator[](const typename object_t::key_type&) for unchecked
access by reference
@sa @ref value() for access by value with a default value
@since version 1.0.0
@liveexample{The example below shows how object elements can be read and
written using `at()`. It also demonstrates the different exceptions that
can be thrown.,at__object_t_key_type}
*/
reference at(const typename object_t::key_type& key)
{
// at only works for objects
if (JSON_LIKELY(is_object()))
{
JSON_TRY
{
return m_value.object->at(key);
}
JSON_CATCH (std::out_of_range&)
{
// create better exception explanation
JSON_THROW(out_of_range::create(403, “key ‘” + key + “‘ not found”));
}
}
else
{
JSON_THROW(type_error::create(304, “cannot use at() with ” + std::string(type_name())));
}
}
/*!
@brief access specified object element with bounds checking
Returns a const reference to the element at with specified key @a key,
with bounds checking.
@param[in] key key of the element to access
@return const reference to the element at key @a key
@throw type_error.304 if the JSON value is not an object; in this case,
calling `at` with a key makes no sense. See example below.
@throw out_of_range.403 if the key @a key is is not stored in the object;
that is, `find(key) == end()`. See example below.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes in the JSON value.
@complexity Logarithmic in the size of the container.
@sa @ref operator[](const typename object_t::key_type&) for unchecked
access by reference
@sa @ref value() for access by value with a default value
@since version 1.0.0
@liveexample{The example below shows how object elements can be read using
`at()`. It also demonstrates the different exceptions that can be thrown.,
at__object_t_key_type_const}
*/
const_reference at(const typename object_t::key_type& key) const
{
// at only works for objects
if (JSON_LIKELY(is_object()))
{
JSON_TRY
{
return m_value.object->at(key);
}
JSON_CATCH (std::out_of_range&)
{
// create better exception explanation
JSON_THROW(out_of_range::create(403, “key ‘” + key + “‘ not found”));
}
}
else
{
JSON_THROW(type_error::create(304, “cannot use at() with ” + std::string(type_name())));
}
}
/*!
@brief access specified array element
Returns a reference to the element at specified location @a idx.
@note If @a idx is beyond the range of the array (i.e., `idx >= size()`),
then the array is silently filled up with `null` values to make `idx` a
valid reference to the last stored element.
@param[in] idx index of the element to access
@return reference to the element at index @a idx
@throw type_error.305 if the JSON value is not an array or null; in that
cases, using the [] operator with an index makes no sense.
@complexity Constant if @a idx is in the range of the array. Otherwise
linear in `idx – size()`.
@liveexample{The example below shows how array elements can be read and
written using `[]` operator. Note the addition of `null`
values.,operatorarray__size_type}
@since version 1.0.0
*/
reference operator[](size_type idx)
{
// implicitly convert null value to an empty array
if (is_null())
{
m_type = value_t::array;
m_value.array = create();
assert_invariant();
}
// operator[] only works for arrays
if (JSON_LIKELY(is_array()))
{
// fill up array with null values if given idx is outside range
if (idx >= m_value.array->size())
{
m_value.array->insert(m_value.array->end(),
idx – m_value.array->size() + 1,
basic_json());
}
return m_value.array->operator[](idx);
}
JSON_THROW(type_error::create(305, “cannot use operator[] with a numeric argument with ” + std::string(type_name())));
}
/*!
@brief access specified array element
Returns a const reference to the element at specified location @a idx.
@param[in] idx index of the element to access
@return const reference to the element at index @a idx
@throw type_error.305 if the JSON value is not an array; in that case,
using the [] operator with an index makes no sense.
@complexity Constant.
@liveexample{The example below shows how array elements can be read using
the `[]` operator.,operatorarray__size_type_const}
@since version 1.0.0
*/
const_reference operator[](size_type idx) const
{
// const operator[] only works for arrays
if (JSON_LIKELY(is_array()))
{
return m_value.array->operator[](idx);
}
JSON_THROW(type_error::create(305, “cannot use operator[] with a numeric argument with ” + std::string(type_name())));
}
/*!
@brief access specified object element
Returns a reference to the element at with specified key @a key.
@note If @a key is not found in the object, then it is silently added to
the object and filled with a `null` value to make `key` a valid reference.
In case the value was `null` before, it is converted to an object.
@param[in] key key of the element to access
@return reference to the element at key @a key
@throw type_error.305 if the JSON value is not an object or null; in that
cases, using the [] operator with a key makes no sense.
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be read and
written using the `[]` operator.,operatorarray__key_type}
@sa @ref at(const typename object_t::key_type&) for access by reference
with range checking
@sa @ref value() for access by value with a default value
@since version 1.0.0
*/
reference operator[](const typename object_t::key_type& key)
{
// implicitly convert null value to an empty object
if (is_null())
{
m_type = value_t::object;
m_value.object = create();
assert_invariant();
}
// operator[] only works for objects
if (JSON_LIKELY(is_object()))
{
return m_value.object->operator[](key);
}
JSON_THROW(type_error::create(305, “cannot use operator[] with a string argument with ” + std::string(type_name())));
}
/*!
@brief read-only access specified object element
Returns a const reference to the element at with specified key @a key. No
bounds checking is performed.
@warning If the element with key @a key does not exist, the behavior is
undefined.
@param[in] key key of the element to access
@return const reference to the element at key @a key
@pre The element with key @a key must exist. **This precondition is
enforced with an assertion.**
@throw type_error.305 if the JSON value is not an object; in that case,
using the [] operator with a key makes no sense.
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be read using
the `[]` operator.,operatorarray__key_type_const}
@sa @ref at(const typename object_t::key_type&) for access by reference
with range checking
@sa @ref value() for access by value with a default value
@since version 1.0.0
*/
const_reference operator[](const typename object_t::key_type& key) const
{
// const operator[] only works for objects
if (JSON_LIKELY(is_object()))
{
assert(m_value.object->find(key) != m_value.object->end());
return m_value.object->find(key)->second;
}
JSON_THROW(type_error::create(305, “cannot use operator[] with a string argument with ” + std::string(type_name())));
}
/*!
@brief access specified object element
Returns a reference to the element at with specified key @a key.
@note If @a key is not found in the object, then it is silently added to
the object and filled with a `null` value to make `key` a valid reference.
In case the value was `null` before, it is converted to an object.
@param[in] key key of the element to access
@return reference to the element at key @a key
@throw type_error.305 if the JSON value is not an object or null; in that
cases, using the [] operator with a key makes no sense.
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be read and
written using the `[]` operator.,operatorarray__key_type}
@sa @ref at(const typename object_t::key_type&) for access by reference
with range checking
@sa @ref value() for access by value with a default value
@since version 1.1.0
*/
template
reference operator[](T* key)
{
// implicitly convert null to object
if (is_null())
{
m_type = value_t::object;
m_value = value_t::object;
assert_invariant();
}
// at only works for objects
if (JSON_LIKELY(is_object()))
{
return m_value.object->operator[](key);
}
JSON_THROW(type_error::create(305, “cannot use operator[] with a string argument with ” + std::string(type_name())));
}
/*!
@brief read-only access specified object element
Returns a const reference to the element at with specified key @a key. No
bounds checking is performed.
@warning If the element with key @a key does not exist, the behavior is
undefined.
@param[in] key key of the element to access
@return const reference to the element at key @a key
@pre The element with key @a key must exist. **This precondition is
enforced with an assertion.**
@throw type_error.305 if the JSON value is not an object; in that case,
using the [] operator with a key makes no sense.
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be read using
the `[]` operator.,operatorarray__key_type_const}
@sa @ref at(const typename object_t::key_type&) for access by reference
with range checking
@sa @ref value() for access by value with a default value
@since version 1.1.0
*/
template
const_reference operator[](T* key) const
{
// at only works for objects
if (JSON_LIKELY(is_object()))
{
assert(m_value.object->find(key) != m_value.object->end());
return m_value.object->find(key)->second;
}
JSON_THROW(type_error::create(305, “cannot use operator[] with a string argument with ” + std::string(type_name())));
}
/*!
@brief access specified object element with default value
Returns either a copy of an object’s element at the specified key @a key
or a given default value if no element with key @a key exists.
The function is basically equivalent to executing
@code {.cpp}
try {
return at(key);
} catch(out_of_range) {
return default_value;
}
@endcode
@note Unlike @ref at(const typename object_t::key_type&), this function
does not throw if the given key @a key was not found.
@note Unlike @ref operator[](const typename object_t::key_type& key), this
function does not implicitly add an element to the position defined by @a
key. This function is furthermore also applicable to const objects.
@param[in] key key of the element to access
@param[in] default_value the value to return if @a key is not found
@tparam ValueType type compatible to JSON values, for instance `int` for
JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for
JSON arrays. Note the type of the expected value at @a key and the default
value @a default_value must be compatible.
@return copy of the element at key @a key or @a default_value if @a key
is not found
@throw type_error.306 if the JSON value is not an object; in that case,
using `value()` with a key makes no sense.
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be queried
with a default value.,basic_json__value}
@sa @ref at(const typename object_t::key_type&) for access by reference
with range checking
@sa @ref operator[](const typename object_t::key_type&) for unchecked
access by reference
@since version 1.0.0
*/
template::value, int>::type = 0>
ValueType value(const typename object_t::key_type& key, const ValueType& default_value) const
{
// at only works for objects
if (JSON_LIKELY(is_object()))
{
// if key is found, return value and given default value otherwise
const auto it = find(key);
if (it != end())
{
return *it;
}
return default_value;
}
JSON_THROW(type_error::create(306, “cannot use value() with ” + std::string(type_name())));
}
/*!
@brief overload for a default value of type const char*
@copydoc basic_json::value(const typename object_t::key_type&, const ValueType&) const
*/
string_t value(const typename object_t::key_type& key, const char* default_value) const
{
return value(key, string_t(default_value));
}
/*!
@brief access specified object element via JSON Pointer with default value
Returns either a copy of an object’s element at the specified key @a key
or a given default value if no element with key @a key exists.
The function is basically equivalent to executing
@code {.cpp}
try {
return at(ptr);
} catch(out_of_range) {
return default_value;
}
@endcode
@note Unlike @ref at(const json_pointer&), this function does not throw
if the given key @a key was not found.
@param[in] ptr a JSON pointer to the element to access
@param[in] default_value the value to return if @a ptr found no value
@tparam ValueType type compatible to JSON values, for instance `int` for
JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for
JSON arrays. Note the type of the expected value at @a key and the default
value @a default_value must be compatible.
@return copy of the element at key @a key or @a default_value if @a key
is not found
@throw type_error.306 if the JSON value is not an object; in that case,
using `value()` with a key makes no sense.
@complexity Logarithmic in the size of the container.
@liveexample{The example below shows how object elements can be queried
with a default value.,basic_json__value_ptr}
@sa @ref operator[](const json_pointer&) for unchecked access by reference
@since version 2.0.2
*/
template::value, int>::type = 0>
ValueType value(const json_pointer& ptr, const ValueType& default_value) const
{
// at only works for objects
if (JSON_LIKELY(is_object()))
{
// if pointer resolves a value, return it or use default value
JSON_TRY
{
return ptr.get_checked(this);
}
JSON_INTERNAL_CATCH (out_of_range&)
{
return default_value;
}
}
JSON_THROW(type_error::create(306, “cannot use value() with ” + std::string(type_name())));
}
/*!
@brief overload for a default value of type const char*
@copydoc basic_json::value(const json_pointer&, ValueType) const
*/
string_t value(const json_pointer& ptr, const char* default_value) const
{
return value(ptr, string_t(default_value));
}
/*!
@brief access the first element
Returns a reference to the first element in the container. For a JSON
container `c`, the expression `c.front()` is equivalent to `*c.begin()`.
@return In case of a structured type (array or object), a reference to the
first element is returned. In case of number, string, or boolean values, a
reference to the value is returned.
@complexity Constant.
@pre The JSON value must not be `null` (would throw `std::out_of_range`)
or an empty array or object (undefined behavior, **guarded by
assertions**).
@post The JSON value remains unchanged.
@throw invalid_iterator.214 when called on `null` value
@liveexample{The following code shows an example for `front()`.,front}
@sa @ref back() — access the last element
@since version 1.0.0
*/
reference front()
{
return *begin();
}
/*!
@copydoc basic_json::front()
*/
const_reference front() const
{
return *cbegin();
}
/*!
@brief access the last element
Returns a reference to the last element in the container. For a JSON
container `c`, the expression `c.back()` is equivalent to
@code {.cpp}
auto tmp = c.end();
–tmp;
return *tmp;
@endcode
@return In case of a structured type (array or object), a reference to the
last element is returned. In case of number, string, or boolean values, a
reference to the value is returned.
@complexity Constant.
@pre The JSON value must not be `null` (would throw `std::out_of_range`)
or an empty array or object (undefined behavior, **guarded by
assertions**).
@post The JSON value remains unchanged.
@throw invalid_iterator.214 when called on a `null` value. See example
below.
@liveexample{The following code shows an example for `back()`.,back}
@sa @ref front() — access the first element
@since version 1.0.0
*/
reference back()
{
auto tmp = end();
–tmp;
return *tmp;
}
/*!
@copydoc basic_json::back()
*/
const_reference back() const
{
auto tmp = cend();
–tmp;
return *tmp;
}
/*!
@brief remove element given an iterator
Removes the element specified by iterator @a pos. The iterator @a pos must
be valid and dereferenceable. Thus the `end()` iterator (which is valid,
but is not dereferenceable) cannot be used as a value for @a pos.
If called on a primitive type other than `null`, the resulting JSON value
will be `null`.
@param[in] pos iterator to the element to remove
@return Iterator following the last removed element. If the iterator @a
pos refers to the last element, the `end()` iterator is returned.
@tparam IteratorType an @ref iterator or @ref const_iterator
@post Invalidates iterators and references at or after the point of the
erase, including the `end()` iterator.
@throw type_error.307 if called on a `null` value; example: `”cannot use
erase() with null”`
@throw invalid_iterator.202 if called on an iterator which does not belong
to the current JSON value; example: `”iterator does not fit current
value”`
@throw invalid_iterator.205 if called on a primitive type with invalid
iterator (i.e., any iterator which is not `begin()`); example: `”iterator
out of range”`
@complexity The complexity depends on the type:
– objects: amortized constant
– arrays: linear in distance between @a pos and the end of the container
– strings: linear in the length of the string
– other types: constant
@liveexample{The example shows the result of `erase()` for different JSON
types.,erase__IteratorType}
@sa @ref erase(IteratorType, IteratorType) — removes the elements in
the given range
@sa @ref erase(const typename object_t::key_type&) — removes the element
from an object at the given key
@sa @ref erase(const size_type) — removes the element from an array at
the given index
@since version 1.0.0
*/
template::value or
std::is_same::value, int>::type
= 0>
IteratorType erase(IteratorType pos)
{
// make sure iterator fits the current value
if (JSON_UNLIKELY(this != pos.m_object))
{
JSON_THROW(invalid_iterator::create(202, “iterator does not fit current value”));
}
IteratorType result = end();
switch (m_type)
{
case value_t::boolean:
case value_t::number_float:
case value_t::number_integer:
case value_t::number_unsigned:
case value_t::string:
{
if (JSON_UNLIKELY(not pos.m_it.primitive_iterator.is_begin()))
{
JSON_THROW(invalid_iterator::create(205, “iterator out of range”));
}
if (is_string())
{
AllocatorType alloc;
std::allocator_traits::destroy(alloc, m_value.string);
std::allocator_traits::deallocate(alloc, m_value.string, 1);
m_value.string = nullptr;
}
m_type = value_t::null;
assert_invariant();
break;
}
case value_t::object:
{
result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator);
break;
}
case value_t::array:
{
result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator);
break;
}
default:
JSON_THROW(type_error::create(307, “cannot use erase() with ” + std::string(type_name())));
}
return result;
}
/*!
@brief remove elements given an iterator range
Removes the element specified by the range `[first; last)`. The iterator
@a first does not need to be dereferenceable if `first == last`: erasing
an empty range is a no-op.
If called on a primitive type other than `null`, the resulting JSON value
will be `null`.
@param[in] first iterator to the beginning of the range to remove
@param[in] last iterator past the end of the range to remove
@return Iterator following the last removed element. If the iterator @a
second refers to the last element, the `end()` iterator is returned.
@tparam IteratorType an @ref iterator or @ref const_iterator
@post Invalidates iterators and references at or after the point of the
erase, including the `end()` iterator.
@throw type_error.307 if called on a `null` value; example: `”cannot use
erase() with null”`
@throw invalid_iterator.203 if called on iterators which does not belong
to the current JSON value; example: `”iterators do not fit current value”`
@throw invalid_iterator.204 if called on a primitive type with invalid
iterators (i.e., if `first != begin()` and `last != end()`); example:
`”iterators out of range”`
@complexity The complexity depends on the type:
– objects: `log(size()) + std::distance(first, last)`
– arrays: linear in the distance between @a first and @a last, plus linear
in the distance between @a last and end of the container
– strings: linear in the length of the string
– other types: constant
@liveexample{The example shows the result of `erase()` for different JSON
types.,erase__IteratorType_IteratorType}
@sa @ref erase(IteratorType) — removes the element at a given position
@sa @ref erase(const typename object_t::key_type&) — removes the element
from an object at the given key
@sa @ref erase(const size_type) — removes the element from an array at
the given index
@since version 1.0.0
*/
template::value or
std::is_same::value, int>::type
= 0>
IteratorType erase(IteratorType first, IteratorType last)
{
// make sure iterator fits the current value
if (JSON_UNLIKELY(this != first.m_object or this != last.m_object))
{
JSON_THROW(invalid_iterator::create(203, “iterators do not fit current value”));
}
IteratorType result = end();
switch (m_type)
{
case value_t::boolean:
case value_t::number_float:
case value_t::number_integer:
case value_t::number_unsigned:
case value_t::string:
{
if (JSON_LIKELY(not first.m_it.primitive_iterator.is_begin()
or not last.m_it.primitive_iterator.is_end()))
{
JSON_THROW(invalid_iterator::create(204, “iterators out of range”));
}
if (is_string())
{
AllocatorType alloc;
std::allocator_traits::destroy(alloc, m_value.string);
std::allocator_traits::deallocate(alloc, m_value.string, 1);
m_value.string = nullptr;
}
m_type = value_t::null;
assert_invariant();
break;
}
case value_t::object:
{
result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator,
last.m_it.object_iterator);
break;
}
case value_t::array:
{
result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator,
last.m_it.array_iterator);
break;
}
default:
JSON_THROW(type_error::create(307, “cannot use erase() with ” + std::string(type_name())));
}
return result;
}
/*!
@brief remove element from a JSON object given a key
Removes elements from a JSON object with the key value @a key.
@param[in] key value of the elements to remove
@return Number of elements removed. If @a ObjectType is the default
`std::map` type, the return value will always be `0` (@a key was not
found) or `1` (@a key was found).
@post References and iterators to the erased elements are invalidated.
Other references and iterators are not affected.
@throw type_error.307 when called on a type other than JSON object;
example: `”cannot use erase() with null”`
@complexity `log(size()) + count(key)`
@liveexample{The example shows the effect of `erase()`.,erase__key_type}
@sa @ref erase(IteratorType) — removes the element at a given position
@sa @ref erase(IteratorType, IteratorType) — removes the elements in
the given range
@sa @ref erase(const size_type) — removes the element from an array at
the given index
@since version 1.0.0
*/
size_type erase(const typename object_t::key_type& key)
{
// this erase only works for objects
if (JSON_LIKELY(is_object()))
{
return m_value.object->erase(key);
}
JSON_THROW(type_error::create(307, “cannot use erase() with ” + std::string(type_name())));
}
/*!
@brief remove element from a JSON array given an index
Removes element from a JSON array at the index @a idx.
@param[in] idx index of the element to remove
@throw type_error.307 when called on a type other than JSON object;
example: `”cannot use erase() with null”`
@throw out_of_range.401 when `idx >= size()`; example: `”array index 17
is out of range”`
@complexity Linear in distance between @a idx and the end of the container.
@liveexample{The example shows the effect of `erase()`.,erase__size_type}
@sa @ref erase(IteratorType) — removes the element at a given position
@sa @ref erase(IteratorType, IteratorType) — removes the elements in
the given range
@sa @ref erase(const typename object_t::key_type&) — removes the element
from an object at the given key
@since version 1.0.0
*/
void erase(const size_type idx)
{
// this erase only works for arrays
if (JSON_LIKELY(is_array()))
{
if (JSON_UNLIKELY(idx >= size()))
{
JSON_THROW(out_of_range::create(401, “array index ” + std::to_string(idx) + ” is out of range”));
}
m_value.array->erase(m_value.array->begin() + static_cast(idx));
}
else
{
JSON_THROW(type_error::create(307, “cannot use erase() with ” + std::string(type_name())));
}
}
/// @}
////////////
// lookup //
////////////
/// @name lookup
/// @{
/*!
@brief find an element in a JSON object
Finds an element in a JSON object with key equivalent to @a key. If the
element is not found or the JSON value is not an object, end() is
returned.
@note This method always returns @ref end() when executed on a JSON type
that is not an object.
@param[in] key key value of the element to search for.
@return Iterator to an element with key equivalent to @a key. If no such
element is found or the JSON value is not an object, past-the-end (see
@ref end()) iterator is returned.
@complexity Logarithmic in the size of the JSON object.
@liveexample{The example shows how `find()` is used.,find__key_type}
@since version 1.0.0
*/
template
iterator find(KeyT&& key)
{
auto result = end();
if (is_object())
{
result.m_it.object_iterator = m_value.object->find(std::forward(key));
}
return result;
}
/*!
@brief find an element in a JSON object
@copydoc find(KeyT&&)
*/
template
const_iterator find(KeyT&& key) const
{
auto result = cend();
if (is_object())
{
result.m_it.object_iterator = m_value.object->find(std::forward(key));
}
return result;
}
/*!
@brief returns the number of occurrences of a key in a JSON object
Returns the number of elements with key @a key. If ObjectType is the
default `std::map` type, the return value will always be `0` (@a key was
not found) or `1` (@a key was found).
@note This method always returns `0` when executed on a JSON type that is
not an object.
@param[in] key key value of the element to count
@return Number of elements with key @a key. If the JSON value is not an
object, the return value will be `0`.
@complexity Logarithmic in the size of the JSON object.
@liveexample{The example shows how `count()` is used.,count}
@since version 1.0.0
*/
template
size_type count(KeyT&& key) const
{
// return 0 for all nonobject types
return is_object() ? m_value.object->count(std::forward(key)) : 0;
}
/// @}
///////////////
// iterators //
///////////////
/// @name iterators
/// @{
/*!
@brief returns an iterator to the first element
Returns an iterator to the first element.
@image html range-begin-end.svg “Illustration from cppreference.com”
@return iterator to the first element
@complexity Constant.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is constant.
@liveexample{The following code shows an example for `begin()`.,begin}
@sa @ref cbegin() — returns a const iterator to the beginning
@sa @ref end() — returns an iterator to the end
@sa @ref cend() — returns a const iterator to the end
@since version 1.0.0
*/
iterator begin() noexcept
{
iterator result(this);
result.set_begin();
return result;
}
/*!
@copydoc basic_json::cbegin()
*/
const_iterator begin() const noexcept
{
return cbegin();
}
/*!
@brief returns a const iterator to the first element
Returns a const iterator to the first element.
@image html range-begin-end.svg “Illustration from cppreference.com”
@return const iterator to the first element
@complexity Constant.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is constant.
– Has the semantics of `const_cast(*this).begin()`.
@liveexample{The following code shows an example for `cbegin()`.,cbegin}
@sa @ref begin() — returns an iterator to the beginning
@sa @ref end() — returns an iterator to the end
@sa @ref cend() — returns a const iterator to the end
@since version 1.0.0
*/
const_iterator cbegin() const noexcept
{
const_iterator result(this);
result.set_begin();
return result;
}
/*!
@brief returns an iterator to one past the last element
Returns an iterator to one past the last element.
@image html range-begin-end.svg “Illustration from cppreference.com”
@return iterator one past the last element
@complexity Constant.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is constant.
@liveexample{The following code shows an example for `end()`.,end}
@sa @ref cend() — returns a const iterator to the end
@sa @ref begin() — returns an iterator to the beginning
@sa @ref cbegin() — returns a const iterator to the beginning
@since version 1.0.0
*/
iterator end() noexcept
{
iterator result(this);
result.set_end();
return result;
}
/*!
@copydoc basic_json::cend()
*/
const_iterator end() const noexcept
{
return cend();
}
/*!
@brief returns a const iterator to one past the last element
Returns a const iterator to one past the last element.
@image html range-begin-end.svg “Illustration from cppreference.com”
@return const iterator one past the last element
@complexity Constant.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is constant.
– Has the semantics of `const_cast(*this).end()`.
@liveexample{The following code shows an example for `cend()`.,cend}
@sa @ref end() — returns an iterator to the end
@sa @ref begin() — returns an iterator to the beginning
@sa @ref cbegin() — returns a const iterator to the beginning
@since version 1.0.0
*/
const_iterator cend() const noexcept
{
const_iterator result(this);
result.set_end();
return result;
}
/*!
@brief returns an iterator to the reverse-beginning
Returns an iterator to the reverse-beginning; that is, the last element.
@image html range-rbegin-rend.svg “Illustration from cppreference.com”
@complexity Constant.
@requirement This function helps `basic_json` satisfying the
[ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer)
requirements:
– The complexity is constant.
– Has the semantics of `reverse_iterator(end())`.
@liveexample{The following code shows an example for `rbegin()`.,rbegin}
@sa @ref crbegin() — returns a const reverse iterator to the beginning
@sa @ref rend() — returns a reverse iterator to the end
@sa @ref crend() — returns a const reverse iterator to the end
@since version 1.0.0
*/
reverse_iterator rbegin() noexcept
{
return reverse_iterator(end());
}
/*!
@copydoc basic_json::crbegin()
*/
const_reverse_iterator rbegin() const noexcept
{
return crbegin();
}
/*!
@brief returns an iterator to the reverse-end
Returns an iterator to the reverse-end; that is, one before the first
element.
@image html range-rbegin-rend.svg “Illustration from cppreference.com”
@complexity Constant.
@requirement This function helps `basic_json` satisfying the
[ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer)
requirements:
– The complexity is constant.
– Has the semantics of `reverse_iterator(begin())`.
@liveexample{The following code shows an example for `rend()`.,rend}
@sa @ref crend() — returns a const reverse iterator to the end
@sa @ref rbegin() — returns a reverse iterator to the beginning
@sa @ref crbegin() — returns a const reverse iterator to the beginning
@since version 1.0.0
*/
reverse_iterator rend() noexcept
{
return reverse_iterator(begin());
}
/*!
@copydoc basic_json::crend()
*/
const_reverse_iterator rend() const noexcept
{
return crend();
}
/*!
@brief returns a const reverse iterator to the last element
Returns a const iterator to the reverse-beginning; that is, the last
element.
@image html range-rbegin-rend.svg “Illustration from cppreference.com”
@complexity Constant.
@requirement This function helps `basic_json` satisfying the
[ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer)
requirements:
– The complexity is constant.
– Has the semantics of `const_cast(*this).rbegin()`.
@liveexample{The following code shows an example for `crbegin()`.,crbegin}
@sa @ref rbegin() — returns a reverse iterator to the beginning
@sa @ref rend() — returns a reverse iterator to the end
@sa @ref crend() — returns a const reverse iterator to the end
@since version 1.0.0
*/
const_reverse_iterator crbegin() const noexcept
{
return const_reverse_iterator(cend());
}
/*!
@brief returns a const reverse iterator to one before the first
Returns a const reverse iterator to the reverse-end; that is, one before
the first element.
@image html range-rbegin-rend.svg “Illustration from cppreference.com”
@complexity Constant.
@requirement This function helps `basic_json` satisfying the
[ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer)
requirements:
– The complexity is constant.
– Has the semantics of `const_cast(*this).rend()`.
@liveexample{The following code shows an example for `crend()`.,crend}
@sa @ref rend() — returns a reverse iterator to the end
@sa @ref rbegin() — returns a reverse iterator to the beginning
@sa @ref crbegin() — returns a const reverse iterator to the beginning
@since version 1.0.0
*/
const_reverse_iterator crend() const noexcept
{
return const_reverse_iterator(cbegin());
}
public:
/*!
@brief wrapper to access iterator member functions in range-based for
This function allows to access @ref iterator::key() and @ref
iterator::value() during range-based for loops. In these loops, a
reference to the JSON values is returned, so there is no access to the
underlying iterator.
For loop without iterator_wrapper:
@code{cpp}
for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
std::cout << "key: " << it.key() << ", value:" << it.value() << '\n';
}
@endcode
Range-based for loop without iterator proxy:
@code{cpp}
for (auto it : j_object)
{
// "it" is of type json::reference and has no key() member
std::cout << "value: " << it << '\n';
}
@endcode
Range-based for loop with iterator proxy:
@code{cpp}
for (auto it : json::iterator_wrapper(j_object))
{
std::cout << "key: " << it.key() << ", value:" << it.value() << '\n';
}
@endcode
@note When iterating over an array, `key()` will return the index of the
element as string (see example).
@param[in] ref reference to a JSON value
@return iteration proxy object wrapping @a ref with an interface to use in
range-based for loops
@liveexample{The following code shows how the wrapper is used,iterator_wrapper}
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes in the JSON value.
@complexity Constant.
@note The name of this function is not yet final and may change in the
future.
@deprecated This stream operator is deprecated and will be removed in
future 4.0.0 of the library. Please use @ref items() instead;
that is, replace `json::iterator_wrapper(j)` with `j.items()`.
*/
JSON_DEPRECATED
static iteration_proxy iterator_wrapper(reference ref) noexcept
{
return ref.items();
}
/*!
@copydoc iterator_wrapper(reference)
*/
JSON_DEPRECATED
static iteration_proxy iterator_wrapper(const_reference ref) noexcept
{
return ref.items();
}
/*!
@brief helper to access iterator member functions in range-based for
This function allows to access @ref iterator::key() and @ref
iterator::value() during range-based for loops. In these loops, a
reference to the JSON values is returned, so there is no access to the
underlying iterator.
For loop without `items()` function:
@code{cpp}
for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
std::cout << "key: " << it.key() << ", value:" << it.value() << '\n';
}
@endcode
Range-based for loop without `items()` function:
@code{cpp}
for (auto it : j_object)
{
// "it" is of type json::reference and has no key() member
std::cout << "value: " << it << '\n';
}
@endcode
Range-based for loop with `items()` function:
@code{cpp}
for (auto& el : j_object.items())
{
std::cout << "key: " << el.key() << ", value:" << el.value() << '\n';
}
@endcode
The `items()` function also allows to use
[structured bindings](https://en.cppreference.com/w/cpp/language/structured_binding)
(C++17):
@code{cpp}
for (auto& [key, val] : j_object.items())
{
std::cout << "key: " << key << ", value:" << val << '\n';
}
@endcode
@note When iterating over an array, `key()` will return the index of the
element as string (see example). For primitive types (e.g., numbers),
`key()` returns an empty string.
@return iteration proxy object wrapping @a ref with an interface to use in
range-based for loops
@liveexample{The following code shows how the function is used.,items}
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes in the JSON value.
@complexity Constant.
@since version 3.1.0, structured bindings support since 3.5.0.
*/
iteration_proxy items() noexcept
{
return iteration_proxy(*this);
}
/*!
@copydoc items()
*/
iteration_proxy items() const noexcept
{
return iteration_proxy(*this);
}
/// @}
//////////////
// capacity //
//////////////
/// @name capacity
/// @{
/*!
@brief checks whether the container is empty.
Checks if a JSON value has no elements (i.e. whether its @ref size is `0`).
@return The return value depends on the different types and is
defined as follows:
Value type | return value
———– | ————-
null | `true`
boolean | `false`
string | `false`
number | `false`
object | result of function `object_t::empty()`
array | result of function `array_t::empty()`
@liveexample{The following code uses `empty()` to check if a JSON
object contains any elements.,empty}
@complexity Constant, as long as @ref array_t and @ref object_t satisfy
the Container concept; that is, their `empty()` functions have constant
complexity.
@iterators No changes.
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@note This function does not return whether a string stored as JSON value
is empty – it returns whether the JSON container itself is empty which is
false in the case of a string.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is constant.
– Has the semantics of `begin() == end()`.
@sa @ref size() — returns the number of elements
@since version 1.0.0
*/
bool empty() const noexcept
{
switch (m_type)
{
case value_t::null:
{
// null values are empty
return true;
}
case value_t::array:
{
// delegate call to array_t::empty()
return m_value.array->empty();
}
case value_t::object:
{
// delegate call to object_t::empty()
return m_value.object->empty();
}
default:
{
// all other types are nonempty
return false;
}
}
}
/*!
@brief returns the number of elements
Returns the number of elements in a JSON value.
@return The return value depends on the different types and is
defined as follows:
Value type | return value
———– | ————-
null | `0`
boolean | `1`
string | `1`
number | `1`
object | result of function object_t::size()
array | result of function array_t::size()
@liveexample{The following code calls `size()` on the different value
types.,size}
@complexity Constant, as long as @ref array_t and @ref object_t satisfy
the Container concept; that is, their size() functions have constant
complexity.
@iterators No changes.
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@note This function does not return the length of a string stored as JSON
value – it returns the number of elements in the JSON value which is 1 in
the case of a string.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is constant.
– Has the semantics of `std::distance(begin(), end())`.
@sa @ref empty() — checks whether the container is empty
@sa @ref max_size() — returns the maximal number of elements
@since version 1.0.0
*/
size_type size() const noexcept
{
switch (m_type)
{
case value_t::null:
{
// null values are empty
return 0;
}
case value_t::array:
{
// delegate call to array_t::size()
return m_value.array->size();
}
case value_t::object:
{
// delegate call to object_t::size()
return m_value.object->size();
}
default:
{
// all other types have size 1
return 1;
}
}
}
/*!
@brief returns the maximum possible number of elements
Returns the maximum number of elements a JSON value is able to hold due to
system or library implementation limitations, i.e. `std::distance(begin(),
end())` for the JSON value.
@return The return value depends on the different types and is
defined as follows:
Value type | return value
———– | ————-
null | `0` (same as `size()`)
boolean | `1` (same as `size()`)
string | `1` (same as `size()`)
number | `1` (same as `size()`)
object | result of function `object_t::max_size()`
array | result of function `array_t::max_size()`
@liveexample{The following code calls `max_size()` on the different value
types. Note the output is implementation specific.,max_size}
@complexity Constant, as long as @ref array_t and @ref object_t satisfy
the Container concept; that is, their `max_size()` functions have constant
complexity.
@iterators No changes.
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@requirement This function helps `basic_json` satisfying the
[Container](https://en.cppreference.com/w/cpp/named_req/Container)
requirements:
– The complexity is constant.
– Has the semantics of returning `b.size()` where `b` is the largest
possible JSON value.
@sa @ref size() — returns the number of elements
@since version 1.0.0
*/
size_type max_size() const noexcept
{
switch (m_type)
{
case value_t::array:
{
// delegate call to array_t::max_size()
return m_value.array->max_size();
}
case value_t::object:
{
// delegate call to object_t::max_size()
return m_value.object->max_size();
}
default:
{
// all other types have max_size() == size()
return size();
}
}
}
/// @}
///////////////
// modifiers //
///////////////
/// @name modifiers
/// @{
/*!
@brief clears the contents
Clears the content of a JSON value and resets it to the default value as
if @ref basic_json(value_t) would have been called with the current value
type from @ref type():
Value type | initial value
———– | ————-
null | `null`
boolean | `false`
string | `””`
number | `0`
object | `{}`
array | `[]`
@post Has the same effect as calling
@code {.cpp}
*this = basic_json(type());
@endcode
@liveexample{The example below shows the effect of `clear()` to different
JSON types.,clear}
@complexity Linear in the size of the JSON value.
@iterators All iterators, pointers and references related to this container
are invalidated.
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@sa @ref basic_json(value_t) — constructor that creates an object with the
same value than calling `clear()`
@since version 1.0.0
*/
void clear() noexcept
{
switch (m_type)
{
case value_t::number_integer:
{
m_value.number_integer = 0;
break;
}
case value_t::number_unsigned:
{
m_value.number_unsigned = 0;
break;
}
case value_t::number_float:
{
m_value.number_float = 0.0;
break;
}
case value_t::boolean:
{
m_value.boolean = false;
break;
}
case value_t::string:
{
m_value.string->clear();
break;
}
case value_t::array:
{
m_value.array->clear();
break;
}
case value_t::object:
{
m_value.object->clear();
break;
}
default:
break;
}
}
/*!
@brief add an object to an array
Appends the given element @a val to the end of the JSON value. If the
function is called on a JSON null value, an empty array is created before
appending @a val.
@param[in] val the value to add to the JSON array
@throw type_error.308 when called on a type other than JSON array or
null; example: `”cannot use push_back() with number”`
@complexity Amortized constant.
@liveexample{The example shows how `push_back()` and `+=` can be used to
add elements to a JSON array. Note how the `null` value was silently
converted to a JSON array.,push_back}
@since version 1.0.0
*/
void push_back(basic_json&& val)
{
// push_back only works for null objects or arrays
if (JSON_UNLIKELY(not(is_null() or is_array())))
{
JSON_THROW(type_error::create(308, “cannot use push_back() with ” + std::string(type_name())));
}
// transform null object into an array
if (is_null())
{
m_type = value_t::array;
m_value = value_t::array;
assert_invariant();
}
// add element to array (move semantics)
m_value.array->push_back(std::move(val));
// invalidate object
val.m_type = value_t::null;
}
/*!
@brief add an object to an array
@copydoc push_back(basic_json&&)
*/
reference operator+=(basic_json&& val)
{
push_back(std::move(val));
return *this;
}
/*!
@brief add an object to an array
@copydoc push_back(basic_json&&)
*/
void push_back(const basic_json& val)
{
// push_back only works for null objects or arrays
if (JSON_UNLIKELY(not(is_null() or is_array())))
{
JSON_THROW(type_error::create(308, “cannot use push_back() with ” + std::string(type_name())));
}
// transform null object into an array
if (is_null())
{
m_type = value_t::array;
m_value = value_t::array;
assert_invariant();
}
// add element to array
m_value.array->push_back(val);
}
/*!
@brief add an object to an array
@copydoc push_back(basic_json&&)
*/
reference operator+=(const basic_json& val)
{
push_back(val);
return *this;
}
/*!
@brief add an object to an object
Inserts the given element @a val to the JSON object. If the function is
called on a JSON null value, an empty object is created before inserting
@a val.
@param[in] val the value to add to the JSON object
@throw type_error.308 when called on a type other than JSON object or
null; example: `”cannot use push_back() with number”`
@complexity Logarithmic in the size of the container, O(log(`size()`)).
@liveexample{The example shows how `push_back()` and `+=` can be used to
add elements to a JSON object. Note how the `null` value was silently
converted to a JSON object.,push_back__object_t__value}
@since version 1.0.0
*/
void push_back(const typename object_t::value_type& val)
{
// push_back only works for null objects or objects
if (JSON_UNLIKELY(not(is_null() or is_object())))
{
JSON_THROW(type_error::create(308, “cannot use push_back() with ” + std::string(type_name())));
}
// transform null object into an object
if (is_null())
{
m_type = value_t::object;
m_value = value_t::object;
assert_invariant();
}
// add element to array
m_value.object->insert(val);
}
/*!
@brief add an object to an object
@copydoc push_back(const typename object_t::value_type&)
*/
reference operator+=(const typename object_t::value_type& val)
{
push_back(val);
return *this;
}
/*!
@brief add an object to an object
This function allows to use `push_back` with an initializer list. In case
1. the current value is an object,
2. the initializer list @a init contains only two elements, and
3. the first element of @a init is a string,
@a init is converted into an object element and added using
@ref push_back(const typename object_t::value_type&). Otherwise, @a init
is converted to a JSON value and added using @ref push_back(basic_json&&).
@param[in] init an initializer list
@complexity Linear in the size of the initializer list @a init.
@note This function is required to resolve an ambiguous overload error,
because pairs like `{“key”, “value”}` can be both interpreted as
`object_t::value_type` or `std::initializer_list`, see
https://github.com/nlohmann/json/issues/235 for more information.
@liveexample{The example shows how initializer lists are treated as
objects when possible.,push_back__initializer_list}
*/
void push_back(initializer_list_t init)
{
if (is_object() and init.size() == 2 and (*init.begin())->is_string())
{
basic_json&& key = init.begin()->moved_or_copied();
push_back(typename object_t::value_type(
std::move(key.get_ref()), (init.begin() + 1)->moved_or_copied()));
}
else
{
push_back(basic_json(init));
}
}
/*!
@brief add an object to an object
@copydoc push_back(initializer_list_t)
*/
reference operator+=(initializer_list_t init)
{
push_back(init);
return *this;
}
/*!
@brief add an object to an array
Creates a JSON value from the passed parameters @a args to the end of the
JSON value. If the function is called on a JSON null value, an empty array
is created before appending the value created from @a args.
@param[in] args arguments to forward to a constructor of @ref basic_json
@tparam Args compatible types to create a @ref basic_json object
@throw type_error.311 when called on a type other than JSON array or
null; example: `”cannot use emplace_back() with number”`
@complexity Amortized constant.
@liveexample{The example shows how `push_back()` can be used to add
elements to a JSON array. Note how the `null` value was silently converted
to a JSON array.,emplace_back}
@since version 2.0.8
*/
template
void emplace_back(Args&& … args)
{
// emplace_back only works for null objects or arrays
if (JSON_UNLIKELY(not(is_null() or is_array())))
{
JSON_THROW(type_error::create(311, “cannot use emplace_back() with ” + std::string(type_name())));
}
// transform null object into an array
if (is_null())
{
m_type = value_t::array;
m_value = value_t::array;
assert_invariant();
}
// add element to array (perfect forwarding)
m_value.array->emplace_back(std::forward(args)…);
}
/*!
@brief add an object to an object if key does not exist
Inserts a new element into a JSON object constructed in-place with the
given @a args if there is no element with the key in the container. If the
function is called on a JSON null value, an empty object is created before
appending the value created from @a args.
@param[in] args arguments to forward to a constructor of @ref basic_json
@tparam Args compatible types to create a @ref basic_json object
@return a pair consisting of an iterator to the inserted element, or the
already-existing element if no insertion happened, and a bool
denoting whether the insertion took place.
@throw type_error.311 when called on a type other than JSON object or
null; example: `”cannot use emplace() with number”`
@complexity Logarithmic in the size of the container, O(log(`size()`)).
@liveexample{The example shows how `emplace()` can be used to add elements
to a JSON object. Note how the `null` value was silently converted to a
JSON object. Further note how no value is added if there was already one
value stored with the same key.,emplace}
@since version 2.0.8
*/
template
std::pair emplace(Args&& … args)
{
// emplace only works for null objects or arrays
if (JSON_UNLIKELY(not(is_null() or is_object())))
{
JSON_THROW(type_error::create(311, “cannot use emplace() with ” + std::string(type_name())));
}
// transform null object into an object
if (is_null())
{
m_type = value_t::object;
m_value = value_t::object;
assert_invariant();
}
// add element to array (perfect forwarding)
auto res = m_value.object->emplace(std::forward(args)…);
// create result iterator and set iterator to the result of emplace
auto it = begin();
it.m_it.object_iterator = res.first;
// return pair of iterator and boolean
return {it, res.second};
}
/// Helper for insertion of an iterator
/// @note: This uses std::distance to support GCC 4.8,
/// see https://github.com/nlohmann/json/pull/1257
template
iterator insert_iterator(const_iterator pos, Args&& … args)
{
iterator result(this);
assert(m_value.array != nullptr);
auto insert_pos = std::distance(m_value.array->begin(), pos.m_it.array_iterator);
m_value.array->insert(pos.m_it.array_iterator, std::forward(args)…);
result.m_it.array_iterator = m_value.array->begin() + insert_pos;
// This could have been written as:
// result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val);
// but the return value of insert is missing in GCC 4.8, so it is written this way instead.
return result;
}
/*!
@brief inserts element
Inserts element @a val before iterator @a pos.
@param[in] pos iterator before which the content will be inserted; may be
the end() iterator
@param[in] val element to insert
@return iterator pointing to the inserted @a val.
@throw type_error.309 if called on JSON values other than arrays;
example: `”cannot use insert() with string”`
@throw invalid_iterator.202 if @a pos is not an iterator of *this;
example: `”iterator does not fit current value”`
@complexity Constant plus linear in the distance between @a pos and end of
the container.
@liveexample{The example shows how `insert()` is used.,insert}
@since version 1.0.0
*/
iterator insert(const_iterator pos, const basic_json& val)
{
// insert only works for arrays
if (JSON_LIKELY(is_array()))
{
// check if iterator pos fits to this JSON value
if (JSON_UNLIKELY(pos.m_object != this))
{
JSON_THROW(invalid_iterator::create(202, “iterator does not fit current value”));
}
// insert to array and return iterator
return insert_iterator(pos, val);
}
JSON_THROW(type_error::create(309, “cannot use insert() with ” + std::string(type_name())));
}
/*!
@brief inserts element
@copydoc insert(const_iterator, const basic_json&)
*/
iterator insert(const_iterator pos, basic_json&& val)
{
return insert(pos, val);
}
/*!
@brief inserts elements
Inserts @a cnt copies of @a val before iterator @a pos.
@param[in] pos iterator before which the content will be inserted; may be
the end() iterator
@param[in] cnt number of copies of @a val to insert
@param[in] val element to insert
@return iterator pointing to the first element inserted, or @a pos if
`cnt==0`
@throw type_error.309 if called on JSON values other than arrays; example:
`”cannot use insert() with string”`
@throw invalid_iterator.202 if @a pos is not an iterator of *this;
example: `”iterator does not fit current value”`
@complexity Linear in @a cnt plus linear in the distance between @a pos
and end of the container.
@liveexample{The example shows how `insert()` is used.,insert__count}
@since version 1.0.0
*/
iterator insert(const_iterator pos, size_type cnt, const basic_json& val)
{
// insert only works for arrays
if (JSON_LIKELY(is_array()))
{
// check if iterator pos fits to this JSON value
if (JSON_UNLIKELY(pos.m_object != this))
{
JSON_THROW(invalid_iterator::create(202, “iterator does not fit current value”));
}
// insert to array and return iterator
return insert_iterator(pos, cnt, val);
}
JSON_THROW(type_error::create(309, “cannot use insert() with ” + std::string(type_name())));
}
/*!
@brief inserts elements
Inserts elements from range `[first, last)` before iterator @a pos.
@param[in] pos iterator before which the content will be inserted; may be
the end() iterator
@param[in] first begin of the range of elements to insert
@param[in] last end of the range of elements to insert
@throw type_error.309 if called on JSON values other than arrays; example:
`”cannot use insert() with string”`
@throw invalid_iterator.202 if @a pos is not an iterator of *this;
example: `”iterator does not fit current value”`
@throw invalid_iterator.210 if @a first and @a last do not belong to the
same JSON value; example: `”iterators do not fit”`
@throw invalid_iterator.211 if @a first or @a last are iterators into
container for which insert is called; example: `”passed iterators may not
belong to container”`
@return iterator pointing to the first element inserted, or @a pos if
`first==last`
@complexity Linear in `std::distance(first, last)` plus linear in the
distance between @a pos and end of the container.
@liveexample{The example shows how `insert()` is used.,insert__range}
@since version 1.0.0
*/
iterator insert(const_iterator pos, const_iterator first, const_iterator last)
{
// insert only works for arrays
if (JSON_UNLIKELY(not is_array()))
{
JSON_THROW(type_error::create(309, “cannot use insert() with ” + std::string(type_name())));
}
// check if iterator pos fits to this JSON value
if (JSON_UNLIKELY(pos.m_object != this))
{
JSON_THROW(invalid_iterator::create(202, “iterator does not fit current value”));
}
// check if range iterators belong to the same JSON object
if (JSON_UNLIKELY(first.m_object != last.m_object))
{
JSON_THROW(invalid_iterator::create(210, “iterators do not fit”));
}
if (JSON_UNLIKELY(first.m_object == this))
{
JSON_THROW(invalid_iterator::create(211, “passed iterators may not belong to container”));
}
// insert to array and return iterator
return insert_iterator(pos, first.m_it.array_iterator, last.m_it.array_iterator);
}
/*!
@brief inserts elements
Inserts elements from initializer list @a ilist before iterator @a pos.
@param[in] pos iterator before which the content will be inserted; may be
the end() iterator
@param[in] ilist initializer list to insert the values from
@throw type_error.309 if called on JSON values other than arrays; example:
`”cannot use insert() with string”`
@throw invalid_iterator.202 if @a pos is not an iterator of *this;
example: `”iterator does not fit current value”`
@return iterator pointing to the first element inserted, or @a pos if
`ilist` is empty
@complexity Linear in `ilist.size()` plus linear in the distance between
@a pos and end of the container.
@liveexample{The example shows how `insert()` is used.,insert__ilist}
@since version 1.0.0
*/
iterator insert(const_iterator pos, initializer_list_t ilist)
{
// insert only works for arrays
if (JSON_UNLIKELY(not is_array()))
{
JSON_THROW(type_error::create(309, “cannot use insert() with ” + std::string(type_name())));
}
// check if iterator pos fits to this JSON value
if (JSON_UNLIKELY(pos.m_object != this))
{
JSON_THROW(invalid_iterator::create(202, “iterator does not fit current value”));
}
// insert to array and return iterator
return insert_iterator(pos, ilist.begin(), ilist.end());
}
/*!
@brief inserts elements
Inserts elements from range `[first, last)`.
@param[in] first begin of the range of elements to insert
@param[in] last end of the range of elements to insert
@throw type_error.309 if called on JSON values other than objects; example:
`”cannot use insert() with string”`
@throw invalid_iterator.202 if iterator @a first or @a last does does not
point to an object; example: `”iterators first and last must point to
objects”`
@throw invalid_iterator.210 if @a first and @a last do not belong to the
same JSON value; example: `”iterators do not fit”`
@complexity Logarithmic: `O(N*log(size() + N))`, where `N` is the number
of elements to insert.
@liveexample{The example shows how `insert()` is used.,insert__range_object}
@since version 3.0.0
*/
void insert(const_iterator first, const_iterator last)
{
// insert only works for objects
if (JSON_UNLIKELY(not is_object()))
{
JSON_THROW(type_error::create(309, “cannot use insert() with ” + std::string(type_name())));
}
// check if range iterators belong to the same JSON object
if (JSON_UNLIKELY(first.m_object != last.m_object))
{
JSON_THROW(invalid_iterator::create(210, “iterators do not fit”));
}
// passed iterators must belong to objects
if (JSON_UNLIKELY(not first.m_object->is_object()))
{
JSON_THROW(invalid_iterator::create(202, “iterators first and last must point to objects”));
}
m_value.object->insert(first.m_it.object_iterator, last.m_it.object_iterator);
}
/*!
@brief updates a JSON object from another object, overwriting existing keys
Inserts all values from JSON object @a j and overwrites existing keys.
@param[in] j JSON object to read values from
@throw type_error.312 if called on JSON values other than objects; example:
`”cannot use update() with string”`
@complexity O(N*log(size() + N)), where N is the number of elements to
insert.
@liveexample{The example shows how `update()` is used.,update}
@sa https://docs.python.org/3.6/library/stdtypes.html#dict.update
@since version 3.0.0
*/
void update(const_reference j)
{
// implicitly convert null value to an empty object
if (is_null())
{
m_type = value_t::object;
m_value.object = create();
assert_invariant();
}
if (JSON_UNLIKELY(not is_object()))
{
JSON_THROW(type_error::create(312, “cannot use update() with ” + std::string(type_name())));
}
if (JSON_UNLIKELY(not j.is_object()))
{
JSON_THROW(type_error::create(312, “cannot use update() with ” + std::string(j.type_name())));
}
for (auto it = j.cbegin(); it != j.cend(); ++it)
{
m_value.object->operator[](it.key()) = it.value();
}
}
/*!
@brief updates a JSON object from another object, overwriting existing keys
Inserts all values from from range `[first, last)` and overwrites existing
keys.
@param[in] first begin of the range of elements to insert
@param[in] last end of the range of elements to insert
@throw type_error.312 if called on JSON values other than objects; example:
`”cannot use update() with string”`
@throw invalid_iterator.202 if iterator @a first or @a last does does not
point to an object; example: `”iterators first and last must point to
objects”`
@throw invalid_iterator.210 if @a first and @a last do not belong to the
same JSON value; example: `”iterators do not fit”`
@complexity O(N*log(size() + N)), where N is the number of elements to
insert.
@liveexample{The example shows how `update()` is used__range.,update}
@sa https://docs.python.org/3.6/library/stdtypes.html#dict.update
@since version 3.0.0
*/
void update(const_iterator first, const_iterator last)
{
// implicitly convert null value to an empty object
if (is_null())
{
m_type = value_t::object;
m_value.object = create();
assert_invariant();
}
if (JSON_UNLIKELY(not is_object()))
{
JSON_THROW(type_error::create(312, “cannot use update() with ” + std::string(type_name())));
}
// check if range iterators belong to the same JSON object
if (JSON_UNLIKELY(first.m_object != last.m_object))
{
JSON_THROW(invalid_iterator::create(210, “iterators do not fit”));
}
// passed iterators must belong to objects
if (JSON_UNLIKELY(not first.m_object->is_object()
or not last.m_object->is_object()))
{
JSON_THROW(invalid_iterator::create(202, “iterators first and last must point to objects”));
}
for (auto it = first; it != last; ++it)
{
m_value.object->operator[](it.key()) = it.value();
}
}
/*!
@brief exchanges the values
Exchanges the contents of the JSON value with those of @a other. Does not
invoke any move, copy, or swap operations on individual elements. All
iterators and references remain valid. The past-the-end iterator is
invalidated.
@param[in,out] other JSON value to exchange the contents with
@complexity Constant.
@liveexample{The example below shows how JSON values can be swapped with
`swap()`.,swap__reference}
@since version 1.0.0
*/
void swap(reference other) noexcept (
std::is_nothrow_move_constructible::value and
std::is_nothrow_move_assignable::value and
std::is_nothrow_move_constructible::value and
std::is_nothrow_move_assignable::value
)
{
std::swap(m_type, other.m_type);
std::swap(m_value, other.m_value);
assert_invariant();
}
/*!
@brief exchanges the values
Exchanges the contents of a JSON array with those of @a other. Does not
invoke any move, copy, or swap operations on individual elements. All
iterators and references remain valid. The past-the-end iterator is
invalidated.
@param[in,out] other array to exchange the contents with
@throw type_error.310 when JSON value is not an array; example: `”cannot
use swap() with string”`
@complexity Constant.
@liveexample{The example below shows how arrays can be swapped with
`swap()`.,swap__array_t}
@since version 1.0.0
*/
void swap(array_t& other)
{
// swap only works for arrays
if (JSON_LIKELY(is_array()))
{
std::swap(*(m_value.array), other);
}
else
{
JSON_THROW(type_error::create(310, “cannot use swap() with ” + std::string(type_name())));
}
}
/*!
@brief exchanges the values
Exchanges the contents of a JSON object with those of @a other. Does not
invoke any move, copy, or swap operations on individual elements. All
iterators and references remain valid. The past-the-end iterator is
invalidated.
@param[in,out] other object to exchange the contents with
@throw type_error.310 when JSON value is not an object; example:
`”cannot use swap() with string”`
@complexity Constant.
@liveexample{The example below shows how objects can be swapped with
`swap()`.,swap__object_t}
@since version 1.0.0
*/
void swap(object_t& other)
{
// swap only works for objects
if (JSON_LIKELY(is_object()))
{
std::swap(*(m_value.object), other);
}
else
{
JSON_THROW(type_error::create(310, “cannot use swap() with ” + std::string(type_name())));
}
}
/*!
@brief exchanges the values
Exchanges the contents of a JSON string with those of @a other. Does not
invoke any move, copy, or swap operations on individual elements. All
iterators and references remain valid. The past-the-end iterator is
invalidated.
@param[in,out] other string to exchange the contents with
@throw type_error.310 when JSON value is not a string; example: `”cannot
use swap() with boolean”`
@complexity Constant.
@liveexample{The example below shows how strings can be swapped with
`swap()`.,swap__string_t}
@since version 1.0.0
*/
void swap(string_t& other)
{
// swap only works for strings
if (JSON_LIKELY(is_string()))
{
std::swap(*(m_value.string), other);
}
else
{
JSON_THROW(type_error::create(310, “cannot use swap() with ” + std::string(type_name())));
}
}
/// @}
public:
//////////////////////////////////////////
// lexicographical comparison operators //
//////////////////////////////////////////
/// @name lexicographical comparison operators
/// @{
/*!
@brief comparison: equal
Compares two JSON values for equality according to the following rules:
– Two JSON values are equal if (1) they are from the same type and (2)
their stored values are the same according to their respective
`operator==`.
– Integer and floating-point numbers are automatically converted before
comparison. Note than two NaN values are always treated as unequal.
– Two JSON null values are equal.
@note Floating-point inside JSON values numbers are compared with
`json::number_float_t::operator==` which is `double::operator==` by
default. To compare floating-point while respecting an epsilon, an alternative
[comparison function](https://github.com/mariokonrad/marnav/blob/master/src/marnav/math/floatingpoint.hpp#L34-#L39)
could be used, for instance
@code {.cpp}
template::value, T>::type>
inline bool is_same(T a, T b, T epsilon = std::numeric_limits::epsilon()) noexcept
{
return std::abs(a – b) <= epsilon;
}
@endcode
@note NaN values never compare equal to themselves or to other NaN values.
@param[in] lhs first JSON value to consider
@param[in] rhs second JSON value to consider
@return whether the values @a lhs and @a rhs are equal
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@complexity Linear.
@liveexample{The example demonstrates comparing several JSON
types.,operator__equal}
@since version 1.0.0
*/
friend bool operator==(const_reference lhs, const_reference rhs) noexcept
{
const auto lhs_type = lhs.type();
const auto rhs_type = rhs.type();
if (lhs_type == rhs_type)
{
switch (lhs_type)
{
case value_t::array:
return (*lhs.m_value.array == *rhs.m_value.array);
case value_t::object:
return (*lhs.m_value.object == *rhs.m_value.object);
case value_t::null:
return true;
case value_t::string:
return (*lhs.m_value.string == *rhs.m_value.string);
case value_t::boolean:
return (lhs.m_value.boolean == rhs.m_value.boolean);
case value_t::number_integer:
return (lhs.m_value.number_integer == rhs.m_value.number_integer);
case value_t::number_unsigned:
return (lhs.m_value.number_unsigned == rhs.m_value.number_unsigned);
case value_t::number_float:
return (lhs.m_value.number_float == rhs.m_value.number_float);
default:
return false;
}
}
else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float)
{
return (static_cast(lhs.m_value.number_integer) == rhs.m_value.number_float);
}
else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer)
{
return (lhs.m_value.number_float == static_cast(rhs.m_value.number_integer));
}
else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float)
{
return (static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_float);
}
else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned)
{
return (lhs.m_value.number_float == static_cast(rhs.m_value.number_unsigned));
}
else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer)
{
return (static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_integer);
}
else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned)
{
return (lhs.m_value.number_integer == static_cast(rhs.m_value.number_unsigned));
}
return false;
}
/*!
@brief comparison: equal
@copydoc operator==(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator==(const_reference lhs, const ScalarType rhs) noexcept
{
return (lhs == basic_json(rhs));
}
/*!
@brief comparison: equal
@copydoc operator==(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator==(const ScalarType lhs, const_reference rhs) noexcept
{
return (basic_json(lhs) == rhs);
}
/*!
@brief comparison: not equal
Compares two JSON values for inequality by calculating `not (lhs == rhs)`.
@param[in] lhs first JSON value to consider
@param[in] rhs second JSON value to consider
@return whether the values @a lhs and @a rhs are not equal
@complexity Linear.
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@liveexample{The example demonstrates comparing several JSON
types.,operator__notequal}
@since version 1.0.0
*/
friend bool operator!=(const_reference lhs, const_reference rhs) noexcept
{
return not (lhs == rhs);
}
/*!
@brief comparison: not equal
@copydoc operator!=(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator!=(const_reference lhs, const ScalarType rhs) noexcept
{
return (lhs != basic_json(rhs));
}
/*!
@brief comparison: not equal
@copydoc operator!=(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator!=(const ScalarType lhs, const_reference rhs) noexcept
{
return (basic_json(lhs) != rhs);
}
/*!
@brief comparison: less than
Compares whether one JSON value @a lhs is less than another JSON value @a
rhs according to the following rules:
– If @a lhs and @a rhs have the same type, the values are compared using
the default `<` operator.
- Integer and floating-point numbers are automatically converted before
comparison
- In case @a lhs and @a rhs have different types, the values are ignored
and the order of the types is considered, see
@ref operator<(const value_t, const value_t).
@param[in] lhs first JSON value to consider
@param[in] rhs second JSON value to consider
@return whether @a lhs is less than @a rhs
@complexity Linear.
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@liveexample{The example demonstrates comparing several JSON
types.,operator__less}
@since version 1.0.0
*/
friend bool operator<(const_reference lhs, const_reference rhs) noexcept
{
const auto lhs_type = lhs.type();
const auto rhs_type = rhs.type();
if (lhs_type == rhs_type)
{
switch (lhs_type)
{
case value_t::array:
return (*lhs.m_value.array) < (*rhs.m_value.array);
case value_t::object:
return *lhs.m_value.object < *rhs.m_value.object;
case value_t::null:
return false;
case value_t::string:
return *lhs.m_value.string < *rhs.m_value.string;
case value_t::boolean:
return lhs.m_value.boolean < rhs.m_value.boolean;
case value_t::number_integer:
return lhs.m_value.number_integer < rhs.m_value.number_integer;
case value_t::number_unsigned:
return lhs.m_value.number_unsigned < rhs.m_value.number_unsigned;
case value_t::number_float:
return lhs.m_value.number_float < rhs.m_value.number_float;
default:
return false;
}
}
else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float)
{
return static_cast(lhs.m_value.number_integer) < rhs.m_value.number_float;
}
else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer)
{
return lhs.m_value.number_float < static_cast(rhs.m_value.number_integer);
}
else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float)
{
return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_float;
}
else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned)
{
return lhs.m_value.number_float < static_cast(rhs.m_value.number_unsigned);
}
else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned)
{
return lhs.m_value.number_integer < static_cast(rhs.m_value.number_unsigned);
}
else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer)
{
return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_integer;
}
// We only reach this line if we cannot compare values. In that case,
// we compare types. Note we have to call the operator explicitly,
// because MSVC has problems otherwise.
return operator<(lhs_type, rhs_type);
}
/*!
@brief comparison: less than
@copydoc operator<(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator<(const_reference lhs, const ScalarType rhs) noexcept
{
return (lhs < basic_json(rhs));
}
/*!
@brief comparison: less than
@copydoc operator<(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator<(const ScalarType lhs, const_reference rhs) noexcept
{
return (basic_json(lhs) < rhs);
}
/*!
@brief comparison: less than or equal
Compares whether one JSON value @a lhs is less than or equal to another
JSON value by calculating `not (rhs < lhs)`.
@param[in] lhs first JSON value to consider
@param[in] rhs second JSON value to consider
@return whether @a lhs is less than or equal to @a rhs
@complexity Linear.
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@liveexample{The example demonstrates comparing several JSON
types.,operator__greater}
@since version 1.0.0
*/
friend bool operator<=(const_reference lhs, const_reference rhs) noexcept
{
return not (rhs < lhs);
}
/*!
@brief comparison: less than or equal
@copydoc operator<=(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator<=(const_reference lhs, const ScalarType rhs) noexcept
{
return (lhs <= basic_json(rhs));
}
/*!
@brief comparison: less than or equal
@copydoc operator<=(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator<=(const ScalarType lhs, const_reference rhs) noexcept
{
return (basic_json(lhs) <= rhs);
}
/*!
@brief comparison: greater than
Compares whether one JSON value @a lhs is greater than another
JSON value by calculating `not (lhs <= rhs)`.
@param[in] lhs first JSON value to consider
@param[in] rhs second JSON value to consider
@return whether @a lhs is greater than to @a rhs
@complexity Linear.
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@liveexample{The example demonstrates comparing several JSON
types.,operator__lessequal}
@since version 1.0.0
*/
friend bool operator>(const_reference lhs, const_reference rhs) noexcept
{
return not (lhs <= rhs);
}
/*!
@brief comparison: greater than
@copydoc operator>(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator>(const_reference lhs, const ScalarType rhs) noexcept
{
return (lhs > basic_json(rhs));
}
/*!
@brief comparison: greater than
@copydoc operator>(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator>(const ScalarType lhs, const_reference rhs) noexcept
{
return (basic_json(lhs) > rhs);
}
/*!
@brief comparison: greater than or equal
Compares whether one JSON value @a lhs is greater than or equal to another
JSON value by calculating `not (lhs < rhs)`.
@param[in] lhs first JSON value to consider
@param[in] rhs second JSON value to consider
@return whether @a lhs is greater than or equal to @a rhs
@complexity Linear.
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@liveexample{The example demonstrates comparing several JSON
types.,operator__greaterequal}
@since version 1.0.0
*/
friend bool operator>=(const_reference lhs, const_reference rhs) noexcept
{
return not (lhs < rhs);
}
/*!
@brief comparison: greater than or equal
@copydoc operator>=(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator>=(const_reference lhs, const ScalarType rhs) noexcept
{
return (lhs >= basic_json(rhs));
}
/*!
@brief comparison: greater than or equal
@copydoc operator>=(const_reference, const_reference)
*/
template::value, int>::type = 0>
friend bool operator>=(const ScalarType lhs, const_reference rhs) noexcept
{
return (basic_json(lhs) >= rhs);
}
/// @}
///////////////////
// serialization //
///////////////////
/// @name serialization
/// @{
/*!
@brief serialize to stream
Serialize the given JSON value @a j to the output stream @a o. The JSON
value will be serialized using the @ref dump member function.
– The indentation of the output can be controlled with the member variable
`width` of the output stream @a o. For instance, using the manipulator
`std::setw(4)` on @a o sets the indentation level to `4` and the
serialization result is the same as calling `dump(4)`.
– The indentation character can be controlled with the member variable
`fill` of the output stream @a o. For instance, the manipulator
`std::setfill(‘\\t’)` sets indentation to use a tab character rather than
the default space character.
@param[in,out] o stream to serialize to
@param[in] j JSON value to serialize
@return the stream @a o
@throw type_error.316 if a string stored inside the JSON value is not
UTF-8 encoded
@complexity Linear.
@liveexample{The example below shows the serialization with different
parameters to `width` to adjust the indentation level.,operator_serialize}
@since version 1.0.0; indentation character added in version 3.0.0
*/
friend std::ostream& operator<<(std::ostream& o, const basic_json& j)
{
// read width member and use it as indentation parameter if nonzero
const bool pretty_print = (o.width() > 0);
const auto indentation = (pretty_print ? o.width() : 0);
// reset width to 0 for subsequent calls to this stream
o.width(0);
// do the actual serialization
serializer s(detail::output_adapter(o), o.fill());
s.dump(j, pretty_print, false, static_cast(indentation));
return o;
}
/*!
@brief serialize to stream
@deprecated This stream operator is deprecated and will be removed in
future 4.0.0 of the library. Please use
@ref operator<<(std::ostream&, const basic_json&)
instead; that is, replace calls like `j >> o;` with `o << j;`.
@since version 1.0.0; deprecated since version 3.0.0
*/
JSON_DEPRECATED
friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
{
return o << j;
}
/// @}
/////////////////////
// deserialization //
/////////////////////
/// @name deserialization
/// @{
/*!
@brief deserialize from a compatible input
This function reads from a compatible input. Examples are:
- an array of 1-byte values
- strings with character/literal type with size of 1 byte
- input streams
- container with contiguous storage of 1-byte values. Compatible container
types include `std::vector`, `std::string`, `std::array`,
`std::valarray`, and `std::initializer_list`. Furthermore, C-style
arrays can be used with `std::begin()`/`std::end()`. User-defined
containers can be used as long as they implement random-access iterators
and a contiguous storage.
@pre Each element of the container has a size of 1 byte. Violating this
precondition yields undefined behavior. **This precondition is enforced
with a static assertion.**
@pre The container storage is contiguous. Violating this precondition
yields undefined behavior. **This precondition is enforced with an
assertion.**
@pre Each element of the container has a size of 1 byte. Violating this
precondition yields undefined behavior. **This precondition is enforced
with a static assertion.**
@warning There is no way to enforce all preconditions at compile-time. If
the function is called with a noncompliant container and with
assertions switched off, the behavior is undefined and will most
likely yield segmentation violation.
@param[in] i input to read from
@param[in] cb a parser callback function of type @ref parser_callback_t
which is used to control the deserialization by filtering unwanted values
(optional)
@param[in] allow_exceptions whether to throw exceptions in case of a
parse error (optional, true by default)
@return deserialized JSON value; in case of a parse error and
@a allow_exceptions set to `false`, the return value will be
value_t::discarded.
@throw parse_error.101 if a parse error occurs; example: `""unexpected end
of input; expected string literal""`
@throw parse_error.102 if to_unicode fails or surrogate error
@throw parse_error.103 if to_unicode fails
@complexity Linear in the length of the input. The parser is a predictive
LL(1) parser. The complexity can be higher if the parser callback function
@a cb has a super-linear complexity.
@note A UTF-8 byte order mark is silently ignored.
@liveexample{The example below demonstrates the `parse()` function reading
from an array.,parse__array__parser_callback_t}
@liveexample{The example below demonstrates the `parse()` function with
and without callback function.,parse__string__parser_callback_t}
@liveexample{The example below demonstrates the `parse()` function with
and without callback function.,parse__istream__parser_callback_t}
@liveexample{The example below demonstrates the `parse()` function reading
from a contiguous container.,parse__contiguouscontainer__parser_callback_t}
@since version 2.0.3 (contiguous containers)
*/
JSON_NODISCARD
static basic_json parse(detail::input_adapter&& i,
const parser_callback_t cb = nullptr,
const bool allow_exceptions = true)
{
basic_json result;
parser(i, cb, allow_exceptions).parse(true, result);
return result;
}
static bool accept(detail::input_adapter&& i)
{
return parser(i).accept(true);
}
/*!
@brief generate SAX events
The SAX event lister must follow the interface of @ref json_sax.
This function reads from a compatible input. Examples are:
- an array of 1-byte values
- strings with character/literal type with size of 1 byte
- input streams
- container with contiguous storage of 1-byte values. Compatible container
types include `std::vector`, `std::string`, `std::array`,
`std::valarray`, and `std::initializer_list`. Furthermore, C-style
arrays can be used with `std::begin()`/`std::end()`. User-defined
containers can be used as long as they implement random-access iterators
and a contiguous storage.
@pre Each element of the container has a size of 1 byte. Violating this
precondition yields undefined behavior. **This precondition is enforced
with a static assertion.**
@pre The container storage is contiguous. Violating this precondition
yields undefined behavior. **This precondition is enforced with an
assertion.**
@pre Each element of the container has a size of 1 byte. Violating this
precondition yields undefined behavior. **This precondition is enforced
with a static assertion.**
@warning There is no way to enforce all preconditions at compile-time. If
the function is called with a noncompliant container and with
assertions switched off, the behavior is undefined and will most
likely yield segmentation violation.
@param[in] i input to read from
@param[in,out] sax SAX event listener
@param[in] format the format to parse (JSON, CBOR, MessagePack, or UBJSON)
@param[in] strict whether the input has to be consumed completely
@return return value of the last processed SAX event
@throw parse_error.101 if a parse error occurs; example: `""unexpected end
of input; expected string literal""`
@throw parse_error.102 if to_unicode fails or surrogate error
@throw parse_error.103 if to_unicode fails
@complexity Linear in the length of the input. The parser is a predictive
LL(1) parser. The complexity can be higher if the SAX consumer @a sax has
a super-linear complexity.
@note A UTF-8 byte order mark is silently ignored.
@liveexample{The example below demonstrates the `sax_parse()` function
reading from string and processing the events with a user-defined SAX
event consumer.,sax_parse}
@since version 3.2.0
*/
template
static bool sax_parse(detail::input_adapter&& i, SAX* sax,
input_format_t format = input_format_t::json,
const bool strict = true)
{
assert(sax);
switch (format)
{
case input_format_t::json:
return parser(std::move(i)).sax_parse(sax, strict);
default:
return detail::binary_reader(std::move(i)).sax_parse(format, sax, strict);
}
}
/*!
@brief deserialize from an iterator range with contiguous storage
This function reads from an iterator range of a container with contiguous
storage of 1-byte values. Compatible container types include
`std::vector`, `std::string`, `std::array`, `std::valarray`, and
`std::initializer_list`. Furthermore, C-style arrays can be used with
`std::begin()`/`std::end()`. User-defined containers can be used as long
as they implement random-access iterators and a contiguous storage.
@pre The iterator range is contiguous. Violating this precondition yields
undefined behavior. **This precondition is enforced with an assertion.**
@pre Each element in the range has a size of 1 byte. Violating this
precondition yields undefined behavior. **This precondition is enforced
with a static assertion.**
@warning There is no way to enforce all preconditions at compile-time. If
the function is called with noncompliant iterators and with
assertions switched off, the behavior is undefined and will most
likely yield segmentation violation.
@tparam IteratorType iterator of container with contiguous storage
@param[in] first begin of the range to parse (included)
@param[in] last end of the range to parse (excluded)
@param[in] cb a parser callback function of type @ref parser_callback_t
which is used to control the deserialization by filtering unwanted values
(optional)
@param[in] allow_exceptions whether to throw exceptions in case of a
parse error (optional, true by default)
@return deserialized JSON value; in case of a parse error and
@a allow_exceptions set to `false`, the return value will be
value_t::discarded.
@throw parse_error.101 in case of an unexpected token
@throw parse_error.102 if to_unicode fails or surrogate error
@throw parse_error.103 if to_unicode fails
@complexity Linear in the length of the input. The parser is a predictive
LL(1) parser. The complexity can be higher if the parser callback function
@a cb has a super-linear complexity.
@note A UTF-8 byte order mark is silently ignored.
@liveexample{The example below demonstrates the `parse()` function reading
from an iterator range.,parse__iteratortype__parser_callback_t}
@since version 2.0.3
*/
template::iterator_category>::value, int>::type = 0>
static basic_json parse(IteratorType first, IteratorType last,
const parser_callback_t cb = nullptr,
const bool allow_exceptions = true)
{
basic_json result;
parser(detail::input_adapter(first, last), cb, allow_exceptions).parse(true, result);
return result;
}
template::iterator_category>::value, int>::type = 0>
static bool accept(IteratorType first, IteratorType last)
{
return parser(detail::input_adapter(first, last)).accept(true);
}
template::iterator_category>::value, int>::type = 0>
static bool sax_parse(IteratorType first, IteratorType last, SAX* sax)
{
return parser(detail::input_adapter(first, last)).sax_parse(sax);
}
/*!
@brief deserialize from stream
@deprecated This stream operator is deprecated and will be removed in
version 4.0.0 of the library. Please use
@ref operator>>(std::istream&, basic_json&)
instead; that is, replace calls like `j << i;` with `i >> j;`.
@since version 1.0.0; deprecated since version 3.0.0
*/
JSON_DEPRECATED
friend std::istream& operator<<(basic_json& j, std::istream& i)
{
return operator>>(i, j);
}
/*!
@brief deserialize from stream
Deserializes an input stream to a JSON value.
@param[in,out] i input stream to read a serialized JSON value from
@param[in,out] j JSON value to write the deserialized input to
@throw parse_error.101 in case of an unexpected token
@throw parse_error.102 if to_unicode fails or surrogate error
@throw parse_error.103 if to_unicode fails
@complexity Linear in the length of the input. The parser is a predictive
LL(1) parser.
@note A UTF-8 byte order mark is silently ignored.
@liveexample{The example below shows how a JSON value is constructed by
reading a serialization from a stream.,operator_deserialize}
@sa parse(std::istream&, const parser_callback_t) for a variant with a
parser callback function to filter values while parsing
@since version 1.0.0
*/
friend std::istream& operator>>(std::istream& i, basic_json& j)
{
parser(detail::input_adapter(i)).parse(false, j);
return i;
}
/// @}
///////////////////////////
// convenience functions //
///////////////////////////
/*!
@brief return the type as string
Returns the type name as string to be used in error messages – usually to
indicate that a function was called on a wrong JSON type.
@return a string representation of a the @a m_type member:
Value type | return value
———– | ————-
null | `”null”`
boolean | `”boolean”`
string | `”string”`
number | `”number”` (for all number types)
object | `”object”`
array | `”array”`
discarded | `”discarded”`
@exceptionsafety No-throw guarantee: this function never throws exceptions.
@complexity Constant.
@liveexample{The following code exemplifies `type_name()` for all JSON
types.,type_name}
@sa @ref type() — return the type of the JSON value
@sa @ref operator value_t() — return the type of the JSON value (implicit)
@since version 1.0.0, public since 2.1.0, `const char*` and `noexcept`
since 3.0.0
*/
const char* type_name() const noexcept
{
{
switch (m_type)
{
case value_t::null:
return “null”;
case value_t::object:
return “object”;
case value_t::array:
return “array”;
case value_t::string:
return “string”;
case value_t::boolean:
return “boolean”;
case value_t::discarded:
return “discarded”;
default:
return “number”;
}
}
}
private:
//////////////////////
// member variables //
//////////////////////
/// the type of the current element
value_t m_type = value_t::null;
/// the value of the current element
json_value m_value = {};
//////////////////////////////////////////
// binary serialization/deserialization //
//////////////////////////////////////////
/// @name binary serialization/deserialization support
/// @{
public:
/*!
@brief create a CBOR serialization of a given JSON value
Serializes a given JSON value @a j to a byte vector using the CBOR (Concise
Binary Object Representation) serialization format. CBOR is a binary
serialization format which aims to be more compact than JSON itself, yet
more efficient to parse.
The library uses the following mapping from JSON values types to
CBOR types according to the CBOR specification (RFC 7049):
JSON value type | value/range | CBOR type | first byte
————— | —————————————— | ———————————- | —————
null | `null` | Null | 0xF6
boolean | `true` | True | 0xF5
boolean | `false` | False | 0xF4
number_integer | -9223372036854775808..-2147483649 | Negative integer (8 bytes follow) | 0x3B
number_integer | -2147483648..-32769 | Negative integer (4 bytes follow) | 0x3A
number_integer | -32768..-129 | Negative integer (2 bytes follow) | 0x39
number_integer | -128..-25 | Negative integer (1 byte follow) | 0x38
number_integer | -24..-1 | Negative integer | 0x20..0x37
number_integer | 0..23 | Integer | 0x00..0x17
number_integer | 24..255 | Unsigned integer (1 byte follow) | 0x18
number_integer | 256..65535 | Unsigned integer (2 bytes follow) | 0x19
number_integer | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A
number_integer | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B
number_unsigned | 0..23 | Integer | 0x00..0x17
number_unsigned | 24..255 | Unsigned integer (1 byte follow) | 0x18
number_unsigned | 256..65535 | Unsigned integer (2 bytes follow) | 0x19
number_unsigned | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A
number_unsigned | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B
number_float | *any value* | Double-Precision Float | 0xFB
string | *length*: 0..23 | UTF-8 string | 0x60..0x77
string | *length*: 23..255 | UTF-8 string (1 byte follow) | 0x78
string | *length*: 256..65535 | UTF-8 string (2 bytes follow) | 0x79
string | *length*: 65536..4294967295 | UTF-8 string (4 bytes follow) | 0x7A
string | *length*: 4294967296..18446744073709551615 | UTF-8 string (8 bytes follow) | 0x7B
array | *size*: 0..23 | array | 0x80..0x97
array | *size*: 23..255 | array (1 byte follow) | 0x98
array | *size*: 256..65535 | array (2 bytes follow) | 0x99
array | *size*: 65536..4294967295 | array (4 bytes follow) | 0x9A
array | *size*: 4294967296..18446744073709551615 | array (8 bytes follow) | 0x9B
object | *size*: 0..23 | map | 0xA0..0xB7
object | *size*: 23..255 | map (1 byte follow) | 0xB8
object | *size*: 256..65535 | map (2 bytes follow) | 0xB9
object | *size*: 65536..4294967295 | map (4 bytes follow) | 0xBA
object | *size*: 4294967296..18446744073709551615 | map (8 bytes follow) | 0xBB
@note The mapping is **complete** in the sense that any JSON value type
can be converted to a CBOR value.
@note If NaN or Infinity are stored inside a JSON number, they are
serialized properly. This behavior differs from the @ref dump()
function which serializes NaN or Infinity to `null`.
@note The following CBOR types are not used in the conversion:
– byte strings (0x40..0x5F)
– UTF-8 strings terminated by “break” (0x7F)
– arrays terminated by “break” (0x9F)
– maps terminated by “break” (0xBF)
– date/time (0xC0..0xC1)
– bignum (0xC2..0xC3)
– decimal fraction (0xC4)
– bigfloat (0xC5)
– tagged items (0xC6..0xD4, 0xD8..0xDB)
– expected conversions (0xD5..0xD7)
– simple values (0xE0..0xF3, 0xF8)
– undefined (0xF7)
– half and single-precision floats (0xF9-0xFA)
– break (0xFF)
@param[in] j JSON value to serialize
@return MessagePack serialization as byte vector
@complexity Linear in the size of the JSON value @a j.
@liveexample{The example shows the serialization of a JSON value to a byte
vector in CBOR format.,to_cbor}
@sa http://cbor.io
@sa @ref from_cbor(detail::input_adapter&&, const bool, const bool) for the
analogous deserialization
@sa @ref to_msgpack(const basic_json&) for the related MessagePack format
@sa @ref to_ubjson(const basic_json&, const bool, const bool) for the
related UBJSON format
@since version 2.0.9
*/
static std::vector to_cbor(const basic_json& j)
{
std::vector result;
to_cbor(j, result);
return result;
}
static void to_cbor(const basic_json& j, detail::output_adapter o)
{
binary_writer(o).write_cbor(j);
}
static void to_cbor(const basic_json& j, detail::output_adapter o)
{
binary_writer(o).write_cbor(j);
}
/*!
@brief create a MessagePack serialization of a given JSON value
Serializes a given JSON value @a j to a byte vector using the MessagePack
serialization format. MessagePack is a binary serialization format which
aims to be more compact than JSON itself, yet more efficient to parse.
The library uses the following mapping from JSON values types to
MessagePack types according to the MessagePack specification:
JSON value type | value/range | MessagePack type | first byte
————— | ——————————— | —————- | ———-
null | `null` | nil | 0xC0
boolean | `true` | true | 0xC3
boolean | `false` | false | 0xC2
number_integer | -9223372036854775808..-2147483649 | int64 | 0xD3
number_integer | -2147483648..-32769 | int32 | 0xD2
number_integer | -32768..-129 | int16 | 0xD1
number_integer | -128..-33 | int8 | 0xD0
number_integer | -32..-1 | negative fixint | 0xE0..0xFF
number_integer | 0..127 | positive fixint | 0x00..0x7F
number_integer | 128..255 | uint 8 | 0xCC
number_integer | 256..65535 | uint 16 | 0xCD
number_integer | 65536..4294967295 | uint 32 | 0xCE
number_integer | 4294967296..18446744073709551615 | uint 64 | 0xCF
number_unsigned | 0..127 | positive fixint | 0x00..0x7F
number_unsigned | 128..255 | uint 8 | 0xCC
number_unsigned | 256..65535 | uint 16 | 0xCD
number_unsigned | 65536..4294967295 | uint 32 | 0xCE
number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xCF
number_float | *any value* | float 64 | 0xCB
string | *length*: 0..31 | fixstr | 0xA0..0xBF
string | *length*: 32..255 | str 8 | 0xD9
string | *length*: 256..65535 | str 16 | 0xDA
string | *length*: 65536..4294967295 | str 32 | 0xDB
array | *size*: 0..15 | fixarray | 0x90..0x9F
array | *size*: 16..65535 | array 16 | 0xDC
array | *size*: 65536..4294967295 | array 32 | 0xDD
object | *size*: 0..15 | fix map | 0x80..0x8F
object | *size*: 16..65535 | map 16 | 0xDE
object | *size*: 65536..4294967295 | map 32 | 0xDF
@note The mapping is **complete** in the sense that any JSON value type
can be converted to a MessagePack value.
@note The following values can **not** be converted to a MessagePack value:
– strings with more than 4294967295 bytes
– arrays with more than 4294967295 elements
– objects with more than 4294967295 elements
@note The following MessagePack types are not used in the conversion:
– bin 8 – bin 32 (0xC4..0xC6)
– ext 8 – ext 32 (0xC7..0xC9)
– float 32 (0xCA)
– fixext 1 – fixext 16 (0xD4..0xD8)
@note Any MessagePack output created @ref to_msgpack can be successfully
parsed by @ref from_msgpack.
@note If NaN or Infinity are stored inside a JSON number, they are
serialized properly. This behavior differs from the @ref dump()
function which serializes NaN or Infinity to `null`.
@param[in] j JSON value to serialize
@return MessagePack serialization as byte vector
@complexity Linear in the size of the JSON value @a j.
@liveexample{The example shows the serialization of a JSON value to a byte
vector in MessagePack format.,to_msgpack}
@sa http://msgpack.org
@sa @ref from_msgpack for the analogous deserialization
@sa @ref to_cbor(const basic_json& for the related CBOR format
@sa @ref to_ubjson(const basic_json&, const bool, const bool) for the
related UBJSON format
@since version 2.0.9
*/
static std::vector to_msgpack(const basic_json& j)
{
std::vector result;
to_msgpack(j, result);
return result;
}
static void to_msgpack(const basic_json& j, detail::output_adapter o)
{
binary_writer(o).write_msgpack(j);
}
static void to_msgpack(const basic_json& j, detail::output_adapter o)
{
binary_writer(o).write_msgpack(j);
}
/*!
@brief create a UBJSON serialization of a given JSON value
Serializes a given JSON value @a j to a byte vector using the UBJSON
(Universal Binary JSON) serialization format. UBJSON aims to be more compact
than JSON itself, yet more efficient to parse.
The library uses the following mapping from JSON values types to
UBJSON types according to the UBJSON specification:
JSON value type | value/range | UBJSON type | marker
————— | ——————————— | ———– | ——
null | `null` | null | `Z`
boolean | `true` | true | `T`
boolean | `false` | false | `F`
number_integer | -9223372036854775808..-2147483649 | int64 | `L`
number_integer | -2147483648..-32769 | int32 | `l`
number_integer | -32768..-129 | int16 | `I`
number_integer | -128..127 | int8 | `i`
number_integer | 128..255 | uint8 | `U`
number_integer | 256..32767 | int16 | `I`
number_integer | 32768..2147483647 | int32 | `l`
number_integer | 2147483648..9223372036854775807 | int64 | `L`
number_unsigned | 0..127 | int8 | `i`
number_unsigned | 128..255 | uint8 | `U`
number_unsigned | 256..32767 | int16 | `I`
number_unsigned | 32768..2147483647 | int32 | `l`
number_unsigned | 2147483648..9223372036854775807 | int64 | `L`
number_float | *any value* | float64 | `D`
string | *with shortest length indicator* | string | `S`
array | *see notes on optimized format* | array | `[`
object | *see notes on optimized format* | map | `{`
@note The mapping is **complete** in the sense that any JSON value type
can be converted to a UBJSON value.
@note The following values can **not** be converted to a UBJSON value:
– strings with more than 9223372036854775807 bytes (theoretical)
– unsigned integer numbers above 9223372036854775807
@note The following markers are not used in the conversion:
– `Z`: no-op values are not created.
– `C`: single-byte strings are serialized with `S` markers.
@note Any UBJSON output created @ref to_ubjson can be successfully parsed
by @ref from_ubjson.
@note If NaN or Infinity are stored inside a JSON number, they are
serialized properly. This behavior differs from the @ref dump()
function which serializes NaN or Infinity to `null`.
@note The optimized formats for containers are supported: Parameter
@a use_size adds size information to the beginning of a container and
removes the closing marker. Parameter @a use_type further checks
whether all elements of a container have the same type and adds the
type marker to the beginning of the container. The @a use_type
parameter must only be used together with @a use_size = true. Note
that @a use_size = true alone may result in larger representations –
the benefit of this parameter is that the receiving side is
immediately informed on the number of elements of the container.
@param[in] j JSON value to serialize
@param[in] use_size whether to add size annotations to container types
@param[in] use_type whether to add type annotations to container types
(must be combined with @a use_size = true)
@return UBJSON serialization as byte vector
@complexity Linear in the size of the JSON value @a j.
@liveexample{The example shows the serialization of a JSON value to a byte
vector in UBJSON format.,to_ubjson}
@sa http://ubjson.org
@sa @ref from_ubjson(detail::input_adapter&&, const bool, const bool) for the
analogous deserialization
@sa @ref to_cbor(const basic_json& for the related CBOR format
@sa @ref to_msgpack(const basic_json&) for the related MessagePack format
@since version 3.1.0
*/
static std::vector to_ubjson(const basic_json& j,
const bool use_size = false,
const bool use_type = false)
{
std::vector result;
to_ubjson(j, result, use_size, use_type);
return result;
}
static void to_ubjson(const basic_json& j, detail::output_adapter o,
const bool use_size = false, const bool use_type = false)
{
binary_writer(o).write_ubjson(j, use_size, use_type);
}
static void to_ubjson(const basic_json& j, detail::output_adapter o,
const bool use_size = false, const bool use_type = false)
{
binary_writer(o).write_ubjson(j, use_size, use_type);
}
/*!
@brief Serializes the given JSON object `j` to BSON and returns a vector
containing the corresponding BSON-representation.
BSON (Binary JSON) is a binary format in which zero or more ordered key/value pairs are
stored as a single entity (a so-called document).
The library uses the following mapping from JSON values types to BSON types:
JSON value type | value/range | BSON type | marker
————— | ——————————— | ———– | ——
null | `null` | null | 0x0A
boolean | `true`, `false` | boolean | 0x08
number_integer | -9223372036854775808..-2147483649 | int64 | 0x12
number_integer | -2147483648..2147483647 | int32 | 0x10
number_integer | 2147483648..9223372036854775807 | int64 | 0x12
number_unsigned | 0..2147483647 | int32 | 0x10
number_unsigned | 2147483648..9223372036854775807 | int64 | 0x12
number_unsigned | 9223372036854775808..18446744073709551615| — | —
number_float | *any value* | double | 0x01
string | *any value* | string | 0x02
array | *any value* | document | 0x04
object | *any value* | document | 0x03
@warning The mapping is **incomplete**, since only JSON-objects (and things
contained therein) can be serialized to BSON.
Also, integers larger than 9223372036854775807 cannot be serialized to BSON,
and the keys may not contain U+0000, since they are serialized a
zero-terminated c-strings.
@throw out_of_range.407 if `j.is_number_unsigned() && j.get() > 9223372036854775807`
@throw out_of_range.409 if a key in `j` contains a NULL (U+0000)
@throw type_error.317 if `!j.is_object()`
@pre The input `j` is required to be an object: `j.is_object() == true`.
@note Any BSON output created via @ref to_bson can be successfully parsed
by @ref from_bson.
@param[in] j JSON value to serialize
@return BSON serialization as byte vector
@complexity Linear in the size of the JSON value @a j.
@liveexample{The example shows the serialization of a JSON value to a byte
vector in BSON format.,to_bson}
@sa http://bsonspec.org/spec.html
@sa @ref from_bson(detail::input_adapter&&, const bool strict) for the
analogous deserialization
@sa @ref to_ubjson(const basic_json&, const bool, const bool) for the
related UBJSON format
@sa @ref to_cbor(const basic_json&) for the related CBOR format
@sa @ref to_msgpack(const basic_json&) for the related MessagePack format
*/
static std::vector to_bson(const basic_json& j)
{
std::vector result;
to_bson(j, result);
return result;
}
/*!
@brief Serializes the given JSON object `j` to BSON and forwards the
corresponding BSON-representation to the given output_adapter `o`.
@param j The JSON object to convert to BSON.
@param o The output adapter that receives the binary BSON representation.
@pre The input `j` shall be an object: `j.is_object() == true`
@sa @ref to_bson(const basic_json&)
*/
static void to_bson(const basic_json& j, detail::output_adapter o)
{
binary_writer(o).write_bson(j);
}
/*!
@copydoc to_bson(const basic_json&, detail::output_adapter)
*/
static void to_bson(const basic_json& j, detail::output_adapter o)
{
binary_writer(o).write_bson(j);
}
/*!
@brief create a JSON value from an input in CBOR format
Deserializes a given input @a i to a JSON value using the CBOR (Concise
Binary Object Representation) serialization format.
The library maps CBOR types to JSON value types as follows:
CBOR type | JSON value type | first byte
———————- | ————— | ———-
Integer | number_unsigned | 0x00..0x17
Unsigned integer | number_unsigned | 0x18
Unsigned integer | number_unsigned | 0x19
Unsigned integer | number_unsigned | 0x1A
Unsigned integer | number_unsigned | 0x1B
Negative integer | number_integer | 0x20..0x37
Negative integer | number_integer | 0x38
Negative integer | number_integer | 0x39
Negative integer | number_integer | 0x3A
Negative integer | number_integer | 0x3B
Negative integer | number_integer | 0x40..0x57
UTF-8 string | string | 0x60..0x77
UTF-8 string | string | 0x78
UTF-8 string | string | 0x79
UTF-8 string | string | 0x7A
UTF-8 string | string | 0x7B
UTF-8 string | string | 0x7F
array | array | 0x80..0x97
array | array | 0x98
array | array | 0x99
array | array | 0x9A
array | array | 0x9B
array | array | 0x9F
map | object | 0xA0..0xB7
map | object | 0xB8
map | object | 0xB9
map | object | 0xBA
map | object | 0xBB
map | object | 0xBF
False | `false` | 0xF4
True | `true` | 0xF5
Null | `null` | 0xF6
Half-Precision Float | number_float | 0xF9
Single-Precision Float | number_float | 0xFA
Double-Precision Float | number_float | 0xFB
@warning The mapping is **incomplete** in the sense that not all CBOR
types can be converted to a JSON value. The following CBOR types
are not supported and will yield parse errors (parse_error.112):
– byte strings (0x40..0x5F)
– date/time (0xC0..0xC1)
– bignum (0xC2..0xC3)
– decimal fraction (0xC4)
– bigfloat (0xC5)
– tagged items (0xC6..0xD4, 0xD8..0xDB)
– expected conversions (0xD5..0xD7)
– simple values (0xE0..0xF3, 0xF8)
– undefined (0xF7)
@warning CBOR allows map keys of any type, whereas JSON only allows
strings as keys in object values. Therefore, CBOR maps with keys
other than UTF-8 strings are rejected (parse_error.113).
@note Any CBOR output created @ref to_cbor can be successfully parsed by
@ref from_cbor.
@param[in] i an input in CBOR format convertible to an input adapter
@param[in] strict whether to expect the input to be consumed until EOF
(true by default)
@param[in] allow_exceptions whether to throw exceptions in case of a
parse error (optional, true by default)
@return deserialized JSON value; in case of a parse error and
@a allow_exceptions set to `false`, the return value will be
value_t::discarded.
@throw parse_error.110 if the given input ends prematurely or the end of
file was not reached when @a strict was set to true
@throw parse_error.112 if unsupported features from CBOR were
used in the given input @a v or if the input is not valid CBOR
@throw parse_error.113 if a string was expected as map key, but not found
@complexity Linear in the size of the input @a i.
@liveexample{The example shows the deserialization of a byte vector in CBOR
format to a JSON value.,from_cbor}
@sa http://cbor.io
@sa @ref to_cbor(const basic_json&) for the analogous serialization
@sa @ref from_msgpack(detail::input_adapter&&, const bool, const bool) for the
related MessagePack format
@sa @ref from_ubjson(detail::input_adapter&&, const bool, const bool) for the
related UBJSON format
@since version 2.0.9; parameter @a start_index since 2.1.1; changed to
consume input adapters, removed start_index parameter, and added
@a strict parameter since 3.0.0; added @a allow_exceptions parameter
since 3.2.0
*/
JSON_NODISCARD
static basic_json from_cbor(detail::input_adapter&& i,
const bool strict = true,
const bool allow_exceptions = true)
{
basic_json result;
detail::json_sax_dom_parser sdp(result, allow_exceptions);
const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::cbor, &sdp, strict);
return res ? result : basic_json(value_t::discarded);
}
/*!
@copydoc from_cbor(detail::input_adapter&&, const bool, const bool)
*/
template::value, int> = 0>
JSON_NODISCARD
static basic_json from_cbor(A1 && a1, A2 && a2,
const bool strict = true,
const bool allow_exceptions = true)
{
basic_json result;
detail::json_sax_dom_parser sdp(result, allow_exceptions);
const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::cbor, &sdp, strict);
return res ? result : basic_json(value_t::discarded);
}
/*!
@brief create a JSON value from an input in MessagePack format
Deserializes a given input @a i to a JSON value using the MessagePack
serialization format.
The library maps MessagePack types to JSON value types as follows:
MessagePack type | JSON value type | first byte
—————- | ————— | ———-
positive fixint | number_unsigned | 0x00..0x7F
fixmap | object | 0x80..0x8F
fixarray | array | 0x90..0x9F
fixstr | string | 0xA0..0xBF
nil | `null` | 0xC0
false | `false` | 0xC2
true | `true` | 0xC3
float 32 | number_float | 0xCA
float 64 | number_float | 0xCB
uint 8 | number_unsigned | 0xCC
uint 16 | number_unsigned | 0xCD
uint 32 | number_unsigned | 0xCE
uint 64 | number_unsigned | 0xCF
int 8 | number_integer | 0xD0
int 16 | number_integer | 0xD1
int 32 | number_integer | 0xD2
int 64 | number_integer | 0xD3
str 8 | string | 0xD9
str 16 | string | 0xDA
str 32 | string | 0xDB
array 16 | array | 0xDC
array 32 | array | 0xDD
map 16 | object | 0xDE
map 32 | object | 0xDF
negative fixint | number_integer | 0xE0-0xFF
@warning The mapping is **incomplete** in the sense that not all
MessagePack types can be converted to a JSON value. The following
MessagePack types are not supported and will yield parse errors:
– bin 8 – bin 32 (0xC4..0xC6)
– ext 8 – ext 32 (0xC7..0xC9)
– fixext 1 – fixext 16 (0xD4..0xD8)
@note Any MessagePack output created @ref to_msgpack can be successfully
parsed by @ref from_msgpack.
@param[in] i an input in MessagePack format convertible to an input
adapter
@param[in] strict whether to expect the input to be consumed until EOF
(true by default)
@param[in] allow_exceptions whether to throw exceptions in case of a
parse error (optional, true by default)
@return deserialized JSON value; in case of a parse error and
@a allow_exceptions set to `false`, the return value will be
value_t::discarded.
@throw parse_error.110 if the given input ends prematurely or the end of
file was not reached when @a strict was set to true
@throw parse_error.112 if unsupported features from MessagePack were
used in the given input @a i or if the input is not valid MessagePack
@throw parse_error.113 if a string was expected as map key, but not found
@complexity Linear in the size of the input @a i.
@liveexample{The example shows the deserialization of a byte vector in
MessagePack format to a JSON value.,from_msgpack}
@sa http://msgpack.org
@sa @ref to_msgpack(const basic_json&) for the analogous serialization
@sa @ref from_cbor(detail::input_adapter&&, const bool, const bool) for the
related CBOR format
@sa @ref from_ubjson(detail::input_adapter&&, const bool, const bool) for
the related UBJSON format
@sa @ref from_bson(detail::input_adapter&&, const bool, const bool) for
the related BSON format
@since version 2.0.9; parameter @a start_index since 2.1.1; changed to
consume input adapters, removed start_index parameter, and added
@a strict parameter since 3.0.0; added @a allow_exceptions parameter
since 3.2.0
*/
JSON_NODISCARD
static basic_json from_msgpack(detail::input_adapter&& i,
const bool strict = true,
const bool allow_exceptions = true)
{
basic_json result;
detail::json_sax_dom_parser sdp(result, allow_exceptions);
const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::msgpack, &sdp, strict);
return res ? result : basic_json(value_t::discarded);
}
/*!
@copydoc from_msgpack(detail::input_adapter&&, const bool, const bool)
*/
template::value, int> = 0>
JSON_NODISCARD
static basic_json from_msgpack(A1 && a1, A2 && a2,
const bool strict = true,
const bool allow_exceptions = true)
{
basic_json result;
detail::json_sax_dom_parser sdp(result, allow_exceptions);
const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::msgpack, &sdp, strict);
return res ? result : basic_json(value_t::discarded);
}
/*!
@brief create a JSON value from an input in UBJSON format
Deserializes a given input @a i to a JSON value using the UBJSON (Universal
Binary JSON) serialization format.
The library maps UBJSON types to JSON value types as follows:
UBJSON type | JSON value type | marker
———– | ————————————— | ——
no-op | *no value, next value is read* | `N`
null | `null` | `Z`
false | `false` | `F`
true | `true` | `T`
float32 | number_float | `d`
float64 | number_float | `D`
uint8 | number_unsigned | `U`
int8 | number_integer | `i`
int16 | number_integer | `I`
int32 | number_integer | `l`
int64 | number_integer | `L`
string | string | `S`
char | string | `C`
array | array (optimized values are supported) | `[`
object | object (optimized values are supported) | `{`
@note The mapping is **complete** in the sense that any UBJSON value can
be converted to a JSON value.
@param[in] i an input in UBJSON format convertible to an input adapter
@param[in] strict whether to expect the input to be consumed until EOF
(true by default)
@param[in] allow_exceptions whether to throw exceptions in case of a
parse error (optional, true by default)
@return deserialized JSON value; in case of a parse error and
@a allow_exceptions set to `false`, the return value will be
value_t::discarded.
@throw parse_error.110 if the given input ends prematurely or the end of
file was not reached when @a strict was set to true
@throw parse_error.112 if a parse error occurs
@throw parse_error.113 if a string could not be parsed successfully
@complexity Linear in the size of the input @a i.
@liveexample{The example shows the deserialization of a byte vector in
UBJSON format to a JSON value.,from_ubjson}
@sa http://ubjson.org
@sa @ref to_ubjson(const basic_json&, const bool, const bool) for the
analogous serialization
@sa @ref from_cbor(detail::input_adapter&&, const bool, const bool) for the
related CBOR format
@sa @ref from_msgpack(detail::input_adapter&&, const bool, const bool) for
the related MessagePack format
@sa @ref from_bson(detail::input_adapter&&, const bool, const bool) for
the related BSON format
@since version 3.1.0; added @a allow_exceptions parameter since 3.2.0
*/
JSON_NODISCARD
static basic_json from_ubjson(detail::input_adapter&& i,
const bool strict = true,
const bool allow_exceptions = true)
{
basic_json result;
detail::json_sax_dom_parser sdp(result, allow_exceptions);
const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::ubjson, &sdp, strict);
return res ? result : basic_json(value_t::discarded);
}
/*!
@copydoc from_ubjson(detail::input_adapter&&, const bool, const bool)
*/
template::value, int> = 0>
JSON_NODISCARD
static basic_json from_ubjson(A1 && a1, A2 && a2,
const bool strict = true,
const bool allow_exceptions = true)
{
basic_json result;
detail::json_sax_dom_parser sdp(result, allow_exceptions);
const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::ubjson, &sdp, strict);
return res ? result : basic_json(value_t::discarded);
}
/*!
@brief Create a JSON value from an input in BSON format
Deserializes a given input @a i to a JSON value using the BSON (Binary JSON)
serialization format.
The library maps BSON record types to JSON value types as follows:
BSON type | BSON marker byte | JSON value type
————— | —————- | —————————
double | 0x01 | number_float
string | 0x02 | string
document | 0x03 | object
array | 0x04 | array
binary | 0x05 | still unsupported
undefined | 0x06 | still unsupported
ObjectId | 0x07 | still unsupported
boolean | 0x08 | boolean
UTC Date-Time | 0x09 | still unsupported
null | 0x0A | null
Regular Expr. | 0x0B | still unsupported
DB Pointer | 0x0C | still unsupported
JavaScript Code | 0x0D | still unsupported
Symbol | 0x0E | still unsupported
JavaScript Code | 0x0F | still unsupported
int32 | 0x10 | number_integer
Timestamp | 0x11 | still unsupported
128-bit decimal float | 0x13 | still unsupported
Max Key | 0x7F | still unsupported
Min Key | 0xFF | still unsupported
@warning The mapping is **incomplete**. The unsupported mappings
are indicated in the table above.
@param[in] i an input in BSON format convertible to an input adapter
@param[in] strict whether to expect the input to be consumed until EOF
(true by default)
@param[in] allow_exceptions whether to throw exceptions in case of a
parse error (optional, true by default)
@return deserialized JSON value; in case of a parse error and
@a allow_exceptions set to `false`, the return value will be
value_t::discarded.
@throw parse_error.114 if an unsupported BSON record type is encountered
@complexity Linear in the size of the input @a i.
@liveexample{The example shows the deserialization of a byte vector in
BSON format to a JSON value.,from_bson}
@sa http://bsonspec.org/spec.html
@sa @ref to_bson(const basic_json&) for the analogous serialization
@sa @ref from_cbor(detail::input_adapter&&, const bool, const bool) for the
related CBOR format
@sa @ref from_msgpack(detail::input_adapter&&, const bool, const bool) for
the related MessagePack format
@sa @ref from_ubjson(detail::input_adapter&&, const bool, const bool) for the
related UBJSON format
*/
JSON_NODISCARD
static basic_json from_bson(detail::input_adapter&& i,
const bool strict = true,
const bool allow_exceptions = true)
{
basic_json result;
detail::json_sax_dom_parser sdp(result, allow_exceptions);
const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::bson, &sdp, strict);
return res ? result : basic_json(value_t::discarded);
}
/*!
@copydoc from_bson(detail::input_adapter&&, const bool, const bool)
*/
template::value, int> = 0>
JSON_NODISCARD
static basic_json from_bson(A1 && a1, A2 && a2,
const bool strict = true,
const bool allow_exceptions = true)
{
basic_json result;
detail::json_sax_dom_parser sdp(result, allow_exceptions);
const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::bson, &sdp, strict);
return res ? result : basic_json(value_t::discarded);
}
/// @}
//////////////////////////
// JSON Pointer support //
//////////////////////////
/// @name JSON Pointer functions
/// @{
/*!
@brief access specified element via JSON Pointer
Uses a JSON pointer to retrieve a reference to the respective JSON value.
No bound checking is performed. Similar to @ref operator[](const typename
object_t::key_type&), `null` values are created in arrays and objects if
necessary.
In particular:
– If the JSON pointer points to an object key that does not exist, it
is created an filled with a `null` value before a reference to it
is returned.
– If the JSON pointer points to an array index that does not exist, it
is created an filled with a `null` value before a reference to it
is returned. All indices between the current maximum and the given
index are also filled with `null`.
– The special value `-` is treated as a synonym for the index past the
end.
@param[in] ptr a JSON pointer
@return reference to the element pointed to by @a ptr
@complexity Constant.
@throw parse_error.106 if an array index begins with ‘0’
@throw parse_error.109 if an array index was not a number
@throw out_of_range.404 if the JSON pointer can not be resolved
@liveexample{The behavior is shown in the example.,operatorjson_pointer}
@since version 2.0.0
*/
reference operator[](const json_pointer& ptr)
{
return ptr.get_unchecked(this);
}
/*!
@brief access specified element via JSON Pointer
Uses a JSON pointer to retrieve a reference to the respective JSON value.
No bound checking is performed. The function does not change the JSON
value; no `null` values are created. In particular, the the special value
`-` yields an exception.
@param[in] ptr JSON pointer to the desired element
@return const reference to the element pointed to by @a ptr
@complexity Constant.
@throw parse_error.106 if an array index begins with ‘0’
@throw parse_error.109 if an array index was not a number
@throw out_of_range.402 if the array index ‘-‘ is used
@throw out_of_range.404 if the JSON pointer can not be resolved
@liveexample{The behavior is shown in the example.,operatorjson_pointer_const}
@since version 2.0.0
*/
const_reference operator[](const json_pointer& ptr) const
{
return ptr.get_unchecked(this);
}
/*!
@brief access specified element via JSON Pointer
Returns a reference to the element at with specified JSON pointer @a ptr,
with bounds checking.
@param[in] ptr JSON pointer to the desired element
@return reference to the element pointed to by @a ptr
@throw parse_error.106 if an array index in the passed JSON pointer @a ptr
begins with ‘0’. See example below.
@throw parse_error.109 if an array index in the passed JSON pointer @a ptr
is not a number. See example below.
@throw out_of_range.401 if an array index in the passed JSON pointer @a ptr
is out of range. See example below.
@throw out_of_range.402 if the array index ‘-‘ is used in the passed JSON
pointer @a ptr. As `at` provides checked access (and no elements are
implicitly inserted), the index ‘-‘ is always invalid. See example below.
@throw out_of_range.403 if the JSON pointer describes a key of an object
which cannot be found. See example below.
@throw out_of_range.404 if the JSON pointer @a ptr can not be resolved.
See example below.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes in the JSON value.
@complexity Constant.
@since version 2.0.0
@liveexample{The behavior is shown in the example.,at_json_pointer}
*/
reference at(const json_pointer& ptr)
{
return ptr.get_checked(this);
}
/*!
@brief access specified element via JSON Pointer
Returns a const reference to the element at with specified JSON pointer @a
ptr, with bounds checking.
@param[in] ptr JSON pointer to the desired element
@return reference to the element pointed to by @a ptr
@throw parse_error.106 if an array index in the passed JSON pointer @a ptr
begins with ‘0’. See example below.
@throw parse_error.109 if an array index in the passed JSON pointer @a ptr
is not a number. See example below.
@throw out_of_range.401 if an array index in the passed JSON pointer @a ptr
is out of range. See example below.
@throw out_of_range.402 if the array index ‘-‘ is used in the passed JSON
pointer @a ptr. As `at` provides checked access (and no elements are
implicitly inserted), the index ‘-‘ is always invalid. See example below.
@throw out_of_range.403 if the JSON pointer describes a key of an object
which cannot be found. See example below.
@throw out_of_range.404 if the JSON pointer @a ptr can not be resolved.
See example below.
@exceptionsafety Strong guarantee: if an exception is thrown, there are no
changes in the JSON value.
@complexity Constant.
@since version 2.0.0
@liveexample{The behavior is shown in the example.,at_json_pointer_const}
*/
const_reference at(const json_pointer& ptr) const
{
return ptr.get_checked(this);
}
/*!
@brief return flattened JSON value
The function creates a JSON object whose keys are JSON pointers (see [RFC
6901](https://tools.ietf.org/html/rfc6901)) and whose values are all
primitive. The original JSON value can be restored using the @ref
unflatten() function.
@return an object that maps JSON pointers to primitive values
@note Empty objects and arrays are flattened to `null` and will not be
reconstructed correctly by the @ref unflatten() function.
@complexity Linear in the size the JSON value.
@liveexample{The following code shows how a JSON object is flattened to an
object whose keys consist of JSON pointers.,flatten}
@sa @ref unflatten() for the reverse function
@since version 2.0.0
*/
basic_json flatten() const
{
basic_json result(value_t::object);
json_pointer::flatten(“”, *this, result);
return result;
}
/*!
@brief unflatten a previously flattened JSON value
The function restores the arbitrary nesting of a JSON value that has been
flattened before using the @ref flatten() function. The JSON value must
meet certain constraints:
1. The value must be an object.
2. The keys must be JSON pointers (see
[RFC 6901](https://tools.ietf.org/html/rfc6901))
3. The mapped values must be primitive JSON types.
@return the original JSON from a flattened version
@note Empty objects and arrays are flattened by @ref flatten() to `null`
values and can not unflattened to their original type. Apart from
this example, for a JSON value `j`, the following is always true:
`j == j.flatten().unflatten()`.
@complexity Linear in the size the JSON value.
@throw type_error.314 if value is not an object
@throw type_error.315 if object values are not primitive
@liveexample{The following code shows how a flattened JSON object is
unflattened into the original nested JSON object.,unflatten}
@sa @ref flatten() for the reverse function
@since version 2.0.0
*/
basic_json unflatten() const
{
return json_pointer::unflatten(*this);
}
/// @}
//////////////////////////
// JSON Patch functions //
//////////////////////////
/// @name JSON Patch functions
/// @{
/*!
@brief applies a JSON patch
[JSON Patch](http://jsonpatch.com) defines a JSON document structure for
expressing a sequence of operations to apply to a JSON) document. With
this function, a JSON Patch is applied to the current JSON value by
executing all operations from the patch.
@param[in] json_patch JSON patch document
@return patched document
@note The application of a patch is atomic: Either all operations succeed
and the patched document is returned or an exception is thrown. In
any case, the original value is not changed: the patch is applied
to a copy of the value.
@throw parse_error.104 if the JSON patch does not consist of an array of
objects
@throw parse_error.105 if the JSON patch is malformed (e.g., mandatory
attributes are missing); example: `”operation add must have member path”`
@throw out_of_range.401 if an array index is out of range.
@throw out_of_range.403 if a JSON pointer inside the patch could not be
resolved successfully in the current JSON value; example: `”key baz not
found”`
@throw out_of_range.405 if JSON pointer has no parent (“add”, “remove”,
“move”)
@throw other_error.501 if “test” operation was unsuccessful
@complexity Linear in the size of the JSON value and the length of the
JSON patch. As usually only a fraction of the JSON value is affected by
the patch, the complexity can usually be neglected.
@liveexample{The following code shows how a JSON patch is applied to a
value.,patch}
@sa @ref diff — create a JSON patch by comparing two JSON values
@sa [RFC 6902 (JSON Patch)](https://tools.ietf.org/html/rfc6902)
@sa [RFC 6901 (JSON Pointer)](https://tools.ietf.org/html/rfc6901)
@since version 2.0.0
*/
basic_json patch(const basic_json& json_patch) const
{
// make a working copy to apply the patch to
basic_json result = *this;
// the valid JSON Patch operations
enum class patch_operations {add, remove, replace, move, copy, test, invalid};
const auto get_op = [](const std::string & op)
{
if (op == “add”)
{
return patch_operations::add;
}
if (op == “remove”)
{
return patch_operations::remove;
}
if (op == “replace”)
{
return patch_operations::replace;
}
if (op == “move”)
{
return patch_operations::move;
}
if (op == “copy”)
{
return patch_operations::copy;
}
if (op == “test”)
{
return patch_operations::test;
}
return patch_operations::invalid;
};
// wrapper for “add” operation; add value at ptr
const auto operation_add = [&result](json_pointer & ptr, basic_json val)
{
// adding to the root of the target document means replacing it
if (ptr.is_root())
{
result = val;
}
else
{
// make sure the top element of the pointer exists
json_pointer top_pointer = ptr.top();
if (top_pointer != ptr)
{
result.at(top_pointer);
}
// get reference to parent of JSON pointer ptr
const auto last_path = ptr.pop_back();
basic_json& parent = result[ptr];
switch (parent.m_type)
{
case value_t::null:
case value_t::object:
{
// use operator[] to add value
parent[last_path] = val;
break;
}
case value_t::array:
{
if (last_path == “-“)
{
// special case: append to back
parent.push_back(val);
}
else
{
const auto idx = json_pointer::array_index(last_path);
if (JSON_UNLIKELY(static_cast(idx) > parent.size()))
{
// avoid undefined behavior
JSON_THROW(out_of_range::create(401, “array index ” + std::to_string(idx) + ” is out of range”));
}
// default case: insert add offset
parent.insert(parent.begin() + static_cast(idx), val);
}
break;
}
// LCOV_EXCL_START
default:
{
// if there exists a parent it cannot be primitive
assert(false);
}
// LCOV_EXCL_STOP
}
}
};
// wrapper for “remove” operation; remove value at ptr
const auto operation_remove = [&result](json_pointer & ptr)
{
// get reference to parent of JSON pointer ptr
const auto last_path = ptr.pop_back();
basic_json& parent = result.at(ptr);
// remove child
if (parent.is_object())
{
// perform range check
auto it = parent.find(last_path);
if (JSON_LIKELY(it != parent.end()))
{
parent.erase(it);
}
else
{
JSON_THROW(out_of_range::create(403, “key ‘” + last_path + “‘ not found”));
}
}
else if (parent.is_array())
{
// note erase performs range check
parent.erase(static_cast(json_pointer::array_index(last_path)));
}
};
// type check: top level value must be an array
if (JSON_UNLIKELY(not json_patch.is_array()))
{
JSON_THROW(parse_error::create(104, 0, “JSON patch must be an array of objects”));
}
// iterate and apply the operations
for (const auto& val : json_patch)
{
// wrapper to get a value for an operation
const auto get_value = [&val](const std::string & op,
const std::string & member,
bool string_type) -> basic_json &
{
// find value
auto it = val.m_value.object->find(member);
// context-sensitive error message
const auto error_msg = (op == “op”) ? “operation” : “operation ‘” + op + “‘”;
// check if desired value is present
if (JSON_UNLIKELY(it == val.m_value.object->end()))
{
JSON_THROW(parse_error::create(105, 0, error_msg + ” must have member ‘” + member + “‘”));
}
// check if result is of type string
if (JSON_UNLIKELY(string_type and not it->second.is_string()))
{
JSON_THROW(parse_error::create(105, 0, error_msg + ” must have string member ‘” + member + “‘”));
}
// no error: return value
return it->second;
};
// type check: every element of the array must be an object
if (JSON_UNLIKELY(not val.is_object()))
{
JSON_THROW(parse_error::create(104, 0, “JSON patch must be an array of objects”));
}
// collect mandatory members
const std::string op = get_value(“op”, “op”, true);
const std::string path = get_value(op, “path”, true);
json_pointer ptr(path);
switch (get_op(op))
{
case patch_operations::add:
{
operation_add(ptr, get_value(“add”, “value”, false));
break;
}
case patch_operations::remove:
{
operation_remove(ptr);
break;
}
case patch_operations::replace:
{
// the “path” location must exist – use at()
result.at(ptr) = get_value(“replace”, “value”, false);
break;
}
case patch_operations::move:
{
const std::string from_path = get_value(“move”, “from”, true);
json_pointer from_ptr(from_path);
// the “from” location must exist – use at()
basic_json v = result.at(from_ptr);
// The move operation is functionally identical to a
// “remove” operation on the “from” location, followed
// immediately by an “add” operation at the target
// location with the value that was just removed.
operation_remove(from_ptr);
operation_add(ptr, v);
break;
}
case patch_operations::copy:
{
const std::string from_path = get_value(“copy”, “from”, true);
const json_pointer from_ptr(from_path);
// the “from” location must exist – use at()
basic_json v = result.at(from_ptr);
// The copy is functionally identical to an “add”
// operation at the target location using the value
// specified in the “from” member.
operation_add(ptr, v);
break;
}
case patch_operations::test:
{
bool success = false;
JSON_TRY
{
// check if “value” matches the one at “path”
// the “path” location must exist – use at()
success = (result.at(ptr) == get_value(“test”, “value”, false));
}
JSON_INTERNAL_CATCH (out_of_range&)
{
// ignore out of range errors: success remains false
}
// throw an exception if test fails
if (JSON_UNLIKELY(not success))
{
JSON_THROW(other_error::create(501, “unsuccessful: ” + val.dump()));
}
break;
}
case patch_operations::invalid:
{
// op must be “add”, “remove”, “replace”, “move”, “copy”, or
// “test”
JSON_THROW(parse_error::create(105, 0, “operation value ‘” + op + “‘ is invalid”));
}
}
}
return result;
}
/*!
@brief creates a diff as a JSON patch
Creates a [JSON Patch](http://jsonpatch.com) so that value @a source can
be changed into the value @a target by calling @ref patch function.
@invariant For two JSON values @a source and @a target, the following code
yields always `true`:
@code {.cpp}
source.patch(diff(source, target)) == target;
@endcode
@note Currently, only `remove`, `add`, and `replace` operations are
generated.
@param[in] source JSON value to compare from
@param[in] target JSON value to compare against
@param[in] path helper value to create JSON pointers
@return a JSON patch to convert the @a source to @a target
@complexity Linear in the lengths of @a source and @a target.
@liveexample{The following code shows how a JSON patch is created as a
diff for two JSON values.,diff}
@sa @ref patch — apply a JSON patch
@sa @ref merge_patch — apply a JSON Merge Patch
@sa [RFC 6902 (JSON Patch)](https://tools.ietf.org/html/rfc6902)
@since version 2.0.0
*/
JSON_NODISCARD
static basic_json diff(const basic_json& source, const basic_json& target,
const std::string& path = “”)
{
// the patch
basic_json result(value_t::array);
// if the values are the same, return empty patch
if (source == target)
{
return result;
}
if (source.type() != target.type())
{
// different types: replace value
result.push_back(
{
{“op”, “replace”}, {“path”, path}, {“value”, target}
});
}
else
{
switch (source.type())
{
case value_t::array:
{
// first pass: traverse common elements
std::size_t i = 0;
while (i < source.size() and i < target.size())
{
// recursive call to compare array values at index i
auto temp_diff = diff(source[i], target[i], path + "/" + std::to_string(i));
result.insert(result.end(), temp_diff.begin(), temp_diff.end());
++i;
}
// i now reached the end of at least one array
// in a second pass, traverse the remaining elements
// remove my remaining elements
const auto end_index = static_cast(result.size());
while (i < source.size())
{
// add operations in reverse order to avoid invalid
// indices
result.insert(result.begin() + end_index, object(
{
{"op", "remove"},
{"path", path + "/" + std::to_string(i)}
}));
++i;
}
// add other remaining elements
while (i < target.size())
{
result.push_back(
{
{"op", "add"},
{"path", path + "/" + std::to_string(i)},
{"value", target[i]}
});
++i;
}
break;
}
case value_t::object:
{
// first pass: traverse this object's elements
for (auto it = source.cbegin(); it != source.cend(); ++it)
{
// escape the key name to be used in a JSON patch
const auto key = json_pointer::escape(it.key());
if (target.find(it.key()) != target.end())
{
// recursive call to compare object values at key it
auto temp_diff = diff(it.value(), target[it.key()], path + "/" + key);
result.insert(result.end(), temp_diff.begin(), temp_diff.end());
}
else
{
// found a key that is not in o -> remove it
result.push_back(object(
{
{“op”, “remove”}, {“path”, path + “/” + key}
}));
}
}
// second pass: traverse other object’s elements
for (auto it = target.cbegin(); it != target.cend(); ++it)
{
if (source.find(it.key()) == source.end())
{
// found a key that is not in this -> add it
const auto key = json_pointer::escape(it.key());
result.push_back(
{
{“op”, “add”}, {“path”, path + “/” + key},
{“value”, it.value()}
});
}
}
break;
}
default:
{
// both primitive type: replace value
result.push_back(
{
{“op”, “replace”}, {“path”, path}, {“value”, target}
});
break;
}
}
}
return result;
}
/// @}
////////////////////////////////
// JSON Merge Patch functions //
////////////////////////////////
/// @name JSON Merge Patch functions
/// @{
/*!
@brief applies a JSON Merge Patch
The merge patch format is primarily intended for use with the HTTP PATCH
method as a means of describing a set of modifications to a target
resource’s content. This function applies a merge patch to the current
JSON value.
The function implements the following algorithm from Section 2 of
[RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396):
“`
define MergePatch(Target, Patch):
if Patch is an Object:
if Target is not an Object:
Target = {} // Ignore the contents and set it to an empty Object
for each Name/Value pair in Patch:
if Value is null:
if Name exists in Target:
remove the Name/Value pair from Target
else:
Target[Name] = MergePatch(Target[Name], Value)
return Target
else:
return Patch
“`
Thereby, `Target` is the current object; that is, the patch is applied to
the current value.
@param[in] apply_patch the patch to apply
@complexity Linear in the lengths of @a patch.
@liveexample{The following code shows how a JSON Merge Patch is applied to
a JSON document.,merge_patch}
@sa @ref patch — apply a JSON patch
@sa [RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396)
@since version 3.0.0
*/
void merge_patch(const basic_json& apply_patch)
{
if (apply_patch.is_object())
{
if (not is_object())
{
*this = object();
}
for (auto it = apply_patch.begin(); it != apply_patch.end(); ++it)
{
if (it.value().is_null())
{
erase(it.key());
}
else
{
operator[](it.key()).merge_patch(it.value());
}
}
}
else
{
*this = apply_patch;
}
}
/// @}
};
} // namespace nlohmann
///////////////////////
// nonmember support //
///////////////////////
// specialization of std::swap, and std::hash
namespace std
{
/// hash value for JSON objects
template<>
struct hash
{
/*!
@brief return a hash value for a JSON object
@since version 1.0.0
*/
std::size_t operator()(const nlohmann::json& j) const
{
// a naive hashing via the string representation
const auto& h = hash();
return h(j.dump());
}
};
/// specialization for std::less
/// @note: do not remove the space after ‘<',
/// see https://github.com/nlohmann/json/pull/679
template<>
struct less< ::nlohmann::detail::value_t>
{
/*!
@brief compare two value_t enum values
@since version 3.0.0
*/
bool operator()(nlohmann::detail::value_t lhs,
nlohmann::detail::value_t rhs) const noexcept
{
return nlohmann::detail::operator<(lhs, rhs);
}
};
/*!
@brief exchanges the values of two JSON objects
@since version 1.0.0
*/
template<>
inline void swap(nlohmann::json& j1, nlohmann::json& j2) noexcept(
is_nothrow_move_constructible::value and
is_nothrow_move_assignable::value
)
{
j1.swap(j2);
}
} // namespace std
/*!
@brief user-defined string literal for JSON values
This operator implements a user-defined string literal for JSON objects. It
can be used by adding `”_json”` to a string literal and returns a JSON object
if no parse error occurred.
@param[in] s a string representation of a JSON object
@param[in] n the length of string @a s
@return a JSON object
@since version 1.0.0
*/
inline nlohmann::json operator “” _json(const char* s, std::size_t n)
{
return nlohmann::json::parse(s, s + n);
}
/*!
@brief user-defined string literal for JSON pointer
This operator implements a user-defined string literal for JSON Pointers. It
can be used by adding `”_json_pointer”` to a string literal and returns a JSON pointer
object if no parse error occurred.
@param[in] s a string representation of a JSON Pointer
@param[in] n the length of string @a s
@return a JSON pointer object
@since version 2.0.0
*/
inline nlohmann::json::json_pointer operator “” _json_pointer(const char* s, std::size_t n)
{
return nlohmann::json::json_pointer(std::string(s, n));
}
// #include
// restore GCC/clang diagnostic settings
#if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__)
#pragma GCC diagnostic pop
#endif
#if defined(__clang__)
#pragma GCC diagnostic pop
#endif
// clean up
#undef JSON_INTERNAL_CATCH
#undef JSON_CATCH
#undef JSON_THROW
#undef JSON_TRY
#undef JSON_LIKELY
#undef JSON_UNLIKELY
#undef JSON_DEPRECATED
#undef JSON_NODISCARD
#undef JSON_HAS_CPP_14
#undef JSON_HAS_CPP_17
#undef NLOHMANN_BASIC_JSON_TPL_DECLARATION
#undef NLOHMANN_BASIC_JSON_TPL
#endif