c++的运算符重载

C++中的加号重载：
例：实现复数的相加

#include<iostream>  
using namespace std;  
  
class Complex{  
    public:  
        Complex(double r=0.0,double i=0.0):real(r),imag(i){}  
        Complex operator+(const Complex &c2)const;  
        void display()const{  
            cout<<"("<<real<<","<<imag<<')'<<endl;  
        }  
    private:  
        double real,imag;  
};  
Complex Complex::operator+(const Complex &c2)const{  
    return Complex(real+c2.real,imag-c2.imag);  
}  
  
int main(){  
    Complex c1(5,4),c2(2,10),c3;  
    c3=c1+c2;  
    c3.display();  
    return 0;  
}  

C++中的前置++重载：
例：点的移动

#include<iostream>  
using namespace std;  
  
class Point{  
    public:  
        Point(float a,float b):x(a),y(b){}  
        Point& operator++();  
        ~Point(){}  
        void dispaly()const{  
            cout<<"("<<x<<","<<y<<")"<<endl;  
        }  
    private:  
        float x,y;  
};  
Point& Point::operator++(){  
    x++;y++;  
    return *this;  
}  
  
int main(){  
    Point p(1,2);  
    (++p).dispaly();  
    p.dispaly();   
    return 0;  
}  

C++中的后置++重载：
例：点的移动

#include<iostream>  
using namespace std;  
  
class Point{  
    public:  
        Point(float a,float b):x(a),y(b){}  
        Point operator++(int);  
        ~Point(){}  
        void dispaly()const{  
            cout<<"("<<x<<","<<y<<")"<<endl;  
        }  
    private:  
        float x,y;  
};  
Point Point::operator++(int){  
    Point p=*this;  
    x++;y++;  
    return p;  
}  
  
int main(){  
    Point p(1,2);  
    (p++).dispaly();  
    p.dispaly();  
    return 0;  
}