定义复数类Complex，重载运算符“+”，使之用于复数的加法运算。将运算符函数重载为非成员、非友元的普通函数。
C++代码实现：
#include<iostream>using namespace std;class Complex{public:Complex(){real=0;imag=0;}Complex(double r,double i){real=r;imag=i;}void get_value();void display();// private:double real;double imag;};Complex operator+(Complex &c1,Complex &c2){return Complex(c1.real+c2.real,c1.imag+c2.imag);}void Complex::get_value(){cin>>real>>imag;}void Complex::display(){cout<<"("<<real<<","<<imag<<"i)"<<endl;}int main(){Complex c1,c2,c3;c1.get_value();c2.get_value();cout<<"c1=";c1.display();cout<<"c2=";c2.display();c3=c1+c2;cout<<"c1+c2="; c3.display();return 0;}
测试样例：
