//头文件#include<iostream>
#include<assert.h>
using namespace std;class Date
{
public:// 获取某年某月的天数int GetMonthDay(int year, int month);// 全缺省的构造函数Date(int year = 1900, int month = 1, int day = 1);// 拷贝构造函数// d2(d1)Date(const Date& d);// 赋值运算符重载// d2 = d3 -> d2.operator=(&d2, d3)Date& operator=(const Date& d);// 析构函数~Date();// 日期+=天数Date& operator+=(int day);// 日期+天数Date operator+(int day);// 日期-天数Date operator-(int day);// 日期-=天数Date& operator-=(int day);// 前置++Date& operator++();// 后置++Date operator++(int);// 后置--Date operator--(int);// 前置--Date& operator--();// >运算符重载bool operator>(const Date& d);// ==运算符重载bool operator==(const Date& d);// >=运算符重载bool operator >= (const Date& d);// <运算符重载bool operator < (const Date& d);// <=运算符重载bool operator <= (const Date& d);// !=运算符重载bool operator != (const Date& d);// 日期-日期 返回天数int operator-(const Date& d);void Print();
private:int _year;int _month;int _day;};

cpp文件

#include"date.h"// 获取某年某月的天数
int Date::GetMonthDay(int year, int month)
{assert(month > 0 && month < 13);static int monthDays[13] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };if (month == 2 && ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0))){return 29;}return monthDays[month];
}// 全缺省的构造函数
Date::Date(int year, int month, int day)
{_year = year;_month = month;_day = day;
}// 拷贝构造函数
// d2(d1)
Date::Date(const Date& d)
{_year = d._year;_month = d._month;_day = d._day;
}// 赋值运算符重载
// d2 = d3 -> d2.operator=(&d2, d3)
Date& Date::operator=(const Date& d)
{_year = d._year;_month = d._month;_day = d._day;return *this;
}// 析构函数
Date::~Date(){}// 日期+=天数
Date& Date::operator+=(int day)
{_day += day;while (_day > GetMonthDay(_year, _month)){_day -= GetMonthDay(_year, _month);_month++;if (_month > 12){_month -= 12;_year++;}}return *this;
}// 日期+天数
Date Date::operator+(int day)
{Date tmp(*this);tmp += day;return tmp;
}// 日期-天数
Date Date::operator-(int day)
{Date tmp(*this);tmp -= (day);return tmp;
}// 日期-=天数
Date& Date::operator-=(int day)
{_day -= day;while (_day < 1){_month--;if (_month < 1){_month += 12;_year--;}_day += GetMonthDay(_year, _month);}return *this;
}// 前置++
Date& Date::operator++()
{*this += 1;return *this;
}// 后置++
Date Date::operator++(int)
{Date tmp(*this);*this += 1;return tmp;
}// 后置--
Date Date::operator--(int)
{Date tmp(*this);*this -= 1;return tmp;
}// 前置--
Date& Date::operator--()
{*this += 1;return *this;
}// >运算符重载
bool Date::operator>(const Date& d)
{if (_year > d._year)return true;else if (_year == d._year && _month > d._month)return true;else if (_year == d._year && _month == d._month && _day > d._day)return true;elsereturn false;
}// ==运算符重载
bool Date::operator==(const Date& d)
{if (_year == d._year && _month == d._month && _day == d._day)return true;
}// >=运算符重载
bool Date::operator >= (const Date& d)
{return *this > d || *this == d;
}// <运算符重载
bool Date::operator < (const Date& d)
{return !(*this >= d);
}// <=运算符重载
bool Date::operator <= (const Date& d)
{return !(*this > d);
}// !=运算符重载
bool Date::operator != (const Date& d)
{return !(*this == d);
}// 日期-日期 返回天数
int Date::operator-(const Date& d)
{int flag = 1;Date max = *this;Date min = d;if (*this < d){int flag = -1;max = d;min = *this;}int n = 0;while (min != max){++min;++n;}return n * flag;
}void Date::Print()
{cout << _year << ' ' << _month << ' ' << _day << endl;
}