C++——定义一个复数类Complex，重载运算符“+”，使之能用于复数的加法。参加运算的两个操作数可以都是类对象，也可以一个是整数，其顺序任意。

没注释的源代码

#include <iostream>

using namespace std;

class Complex

{

public:

    Complex(){real=0;imag=0;}

    Complex(double r,double i){real=r;imag=i;}

    Complex operator+(Complex &c2)

    {

        Complex c;

        c.real=real+c2.real;

        c.imag=imag+c2.imag;

        return c;

    }

    double get_real()

    {

        return real;

    }

    double get_imag()

    {

        return imag;

    }

    Complex operator+(int &i)

    {

        Complex c;

        c.real=real+i;

        c.imag=imag;

        return c;

    }

    void display()

    {

        cout<<"("<<real<<","<<imag<<"i)"<<endl;

    }

    friend Complex operator+(int &i,Complex &c2);

private:

    double real;

    double imag;

};

Complex operator+(int &i,Complex &c2)

{

    Complex c;

    c.real=i+c2.real;

    c.imag=c2.imag;

}

int main()

{

    Complex c1(3,4),c2(5,-10),c3;

    int i=5;

    c3=c1+c2;

    c3.display();

    c3=i+c1;

    c3.display();

    c3=c1+i;

    c3.display();

    return 0;

}