// from : Savitch. Absolute C++.
#pragma once
class DayOfYear
{
public:
DayOfYear();
DayOfYear(int m, int d);
void input();
void output() const;
void set(int newMonth, int newDay);
int getMonthNumber() const;
int getDay() const;
/*
* Return 0 if day of the year represented by obj1 and obj2 are equal
* Return negative number if day of the year represented by obj1 is lesser than obj2
* Return positive number if day of the year represented by obj1 is greater than obj2
*/
int compareAnotherDayOfYear(const DayOfYear other) const;
private:
int month;
int day;
};
// Inline functions’ definitions must be found in the compilation unit in which they are used.
// To achieve that, we may put their definition in the header file in which they are declared.
// Try putting this definition in DayOfYear.cpp, remove it from here, and recompile. You will
// get an error.
//
// In other words, inline functions have internal linkage. If you want to make an inline function
// accessible to other compilation units, they must include the definition of the inline function.
inline int DayOfYear::compareAnotherDayOfYear(const DayOfYear other) const{
int returnVal = getMonthNumber() – other.getMonthNumber();
returnVal = returnVal == 0 ? getDay() – other.getDay() : returnVal;
return returnVal;
}