成员函数重载算数运算符“+”

#include<iostream>
using namespace std;
class Complex{
	public:
		Complex(double r=0,double i=0){
			real=r;
			imag=i;
		}
		void display(){
			cout<<"("<<endl;
			if(imag>0) 
			cout<<"+"<<imag<<"i)";
			else if(imag<0) 
			cout<<imag<<"i)";
			else 
			cout<<")";
		}
		Complex operator+(Complex c);
		private:
			double real,imag;
} ;
Complex Complex::operator+(Complex c){
	Complex cc;
	cc.real=real+c.real;
	cc.imag=imag+c.imag;
	return cc;
}
int main(){
	Complex c1(1.1,2.2),c2(3.3,4.4),c3;
	c3=c1+c2;
	c3.display();
	return 0;
}

以Complex类来说明运算符重载为类的成员函数：
c3=c1.operator+(c2),其中运算符左操作数即c1对象作为了调用运算符重载函数的对象，右操作c2对象则作为函数调用时的参数。