日期类

#define _CRT_SECURE_NO_WARNINGS 1

#include<iostream>
using namespace std;

class Date
{
public:
	Date(int Year=2000,int Month=1,int Day=1)
		:_Year(Year)
		,_Month(Month)
		,_Day(Day)
	{
		if(!IsInvalidDay(_Year,_Month,_Day))
		{
			_Year=2000;
			_Month=1;
			_Day=1;
			cout<<"小同志时间有问题哟"<<endl;
		}
	}

	Date operator+(int count)
	{
		Date tmp(*this);//?
		tmp._Day+=count;
		ToCorrect(tmp);
		return tmp;
	}
	Date operator-(int count)
	{
		Date tmp(*this);
		tmp._Day-=count;
		ToCorrect(tmp);
		return tmp;
	}
	Date& operator++()//前置++，++day
	{
		return (*this=*this+1);
	}
	Date operator++(int)//后置++，day++
	{ 
		Date tmp(*this);
		*this=*this+1;
		return tmp;
	}
	Date& operator--()//前置--,--day
	{
		(*this)--;
		return *this;
	}
	Date operator--(int)//后置--，day--
	{
		Date tmp(*this);
		*this=*this-1;
		return tmp;
	}
	bool operator>(const Date& d)
	{
		 if(this->_Year>d._Year
			||(this->_Year==d._Year && this->_Month>d._Month)
			||(this->_Year==d._Year && this->_Month==d._Month &&_Day>d._Day))
			return true;
		 return false;
	}
	bool operator<(const Date& d)
	{
		 if(this->_Year>d._Year
			||(this->_Year==d._Year && this->_Month>d._Month)
			||(this->_Year==d._Year && this->_Month==d._Month &&_Day>=d._Day))
			return false;
		 return true;
	}
	bool operator==(const Date& d)
	{
		 if(this->_Year==d._Year && this->_Month==d._Month && _Day==d._Day)
			return true;
		 return false;
	}
	bool operator!=(const Date& d)
	{
		 if(this->_Year==d._Year && this->_Month==d._Month && _Day==d._Day)
			return false;
		 return true;
	}
	int operator-(const Date& d)//比较两个日期的差值
	{
		int flag=1;
		Date max=*this;
		Date min=d;
		if(*this<d)
		{
			max=d;
			min=*this;
			flag=-1;
		}
		int count=0;
		while(min!=max)
		{
			min++;
			count++;
		}
		return count*flag;
	}
	Date& operator+=(int count)//count天后的日期
	{
		*this=*this+count;
		return *this;
	}
	Date& operator-=(int count)//count天前的日期
	{
		*this=*this-count;
		return *this;
	}
	virtual ~Date()
	{}
public:
	bool IsInvalidDay(int Year,int Month,int Day)
	{
		if(Year<1 || Month<1 || Month>13
			|| Day>YearOfMonth(Year,Month))
			return false;
		return true;
	}
	int YearOfMonth(int Year,int Month)
	{
		int Day;
		int Days[12]={31,28,31,30,31,30,31,31,30,31,30,31};
		Day=Days[Month-1];
		if(Month==2)
			Day+=IsLeapYear(Year);
			return Day;
	}

	//Date ToCorrect(Date &d)
	//{
	//	if(d._Day<=d.YearOfMonth(d._Year,d._Month))
	//	{
	//		while(d._Day<=0)
	//		{
	//			if(d._Month==1)
	//			{
	//				d._Year--;
	//				d._Month=12;
	//			}
	//			else
	//				d._Month--;
	//			d._Day+=d.YearOfMonth(d._Year,d._Month);
	//		}
	//	}
	//	else
	//	{
	//		while(d._Day>d.YearOfMonth(d._Year,d._Month))
	//		{
	//			d._Day-=d.YearOfMonth(d._Year,d._Month);
	//			if(d._Month==12)
	//			{
	//				d._Year++;
	//				d._Month=1;
	//			}
	//			else
	//				d._Month++;
	//			//d._Day+=d.YearOfMonth(d._Year,d._Month);
	//		}
	//	}
	//	return d;
	//}
	Date ToCorrect(Date &d)
    {
        if (d._Day>YearOfMonth(d._Year, d._Month))
        {
            while (d._Day > YearOfMonth(d._Year, d._Month))
            {
                 d._Day -= YearOfMonth(d._Year,d._Month);

                if (d._Month == 12)
                {
                    d._Year++;
                    d._Month = 1;
                }
                else
                {
                    ++d._Month;
                }
            }
			return d;
        }
        else
        {
            while (d._Day <= 0)
            {
                if (d._Month == 1)
                {
                    d._Year--;
                    d._Month = 12;
                }
                else
                {
                    --d._Month;
                }
                d._Day += YearOfMonth(d._Year, d._Month);
            }
			return d;
        }
    }
	bool IsLeapYear(int Year)
	{
		if(Year%4==0 && Year%100==0
			||Year%400==0)
			return true;
		else
			return false;
	}
	void Display()
	{
		cout<<"Time is:"<<_Year<<"-"<<_Month<<"-"<<_Day<<endl;
	}
	friend istream& operator>>(istream &is,Date &d);
	friend ostream& operator<<(ostream &os,Date &d);
	friend void Test();
private:
	int _Year;
	int _Month;
	int _Day;
};
istream& operator>>(istream &is,Date &d)
{
	cout<<"请输入一个日期"<<endl;
	is>>d._Year>>d._Month>>d._Day;
	return is;
}
ostream& operator<<(ostream &os,Date &d)
{
	cout<<"请输出一个日期"<<endl;
	os<<d._Year<<d._Month<<d._Day;
	return os;
}

　　测试：

void Test()
{
	Date d(2000,1,3);
	//d.operator +(30);
	//d.operator -(30);
	//Date d1(2000,3,27);
	//d.operator -(d1);
	//d.operator +=(32);
	//d.operator -=(21);
	d.Display();
}
int main()
{
	Test();
	return 0;
}

　下面是测试的截图：　（黄色箭头是对应第一个跳入（调用）的函数）