类的加法

#include<iostream>using namespace std;class data{private:    int m, d, y;    static int day[];public:    data(int M, int D, int Y)    {        m = M;        d = D;        y = Y;    }    void display()    {        cout << "年" << y << "月" << m << "日" << d << endl;    }    data operator+(int n)const    {        data Data = *this;        n += Data.d;        while (n > day[Data.m - 1])        {            n -= day[Data.m - 1];            if (++Data.m == 13)            {                Data.m = 1;                Data.y++;            }        }        Data.d = n;        return Data;    }};int data::day[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };int main(){    data d1(03, 05, 2012);    d1.display();    data d2 = d1 + 10;    cout << "加上后" << endl;    d2.display();    system("pause");    return 0;}