8-7

对类Point重载“++”(自增)、“--”(自减)运算符,要求同时重载前缀和后缀的形式。

#include <iostream>
#include <string>
#include<string.h>
#include <stdio.h>
using namespace std;

class Point{
private:
    int x;
    int y;
public:
    Point();
    Point(int, int);
    ~Point(){}
    void ShowPoint(){cout<<"x:"<<x<<" "<<"y:"<<y<<endl;}
    Point& operator ++();
    Point operator ++(int);
    Point& operator --();
    Point operator --(int);
};

Point::Point():x(0), y(0){}

Point::Point(int x, int y):x(x), y(y){}

Point& Point::operator ++(){
    x++;
    y++;
    return *this;
}

Point Point::operator ++(int){
    Point temp = *this;
    ++*this;
    return temp;
}

Point& Point::operator --(){
    x--;
    y--;
    return *this;
}

Point Point::operator --(int){
    Point temp = *this;
    --*this;
    return temp;
}


int main(){
    Point p(1,2);
    p.ShowPoint();
    (p++).ShowPoint();
    (++p).ShowPoint();
    (p--).ShowPoint();
    (--p).ShowPoint();
    return 0;    
}