运算符重载拓展

#include <iostream>
using namespace std;
class Complex
{
public:
    Complex(){real=0;imag=0;}
    Complex(double r,double i){real=r; imag=i;}
    friend Complex operator+(Complex &c1,Complex &c2);
    friend Complex operator+(double d,Complex &c1);
    friend Complex operator+(Complex &c1,double d);
    friend Complex operator-(Complex &c1,Complex &c2);
    friend Complex operator-(double d,Complex &c1);
    friend Complex operator-(Complex &c1,double d);
    friend Complex operator*(Complex &c1,Complex &c2);
    friend Complex operator*(double d,Complex &c1);
    friend Complex operator*(Complex &c1,double d);
    friend Complex operator/(Complex &c1,Complex &c2);
    friend Complex operator/(double d,Complex &c1);
    friend Complex operator/(Complex &c1,double d);
    void display();
private:
    double real;
    double imag;
};
//下面定义友元函数
//加法
Complex operator+(Complex &c1,Complex &c2)
{
    return Complex(c1.real+c2.real,c1.imag+c2.imag);
}
Complex operator+(double d,Complex &c1)
{
    Complex c(d,0);
    return c+c1;
}
Complex operator+(Complex &c1,double d)
{
    Complex c(d,0);
    return c+c1;
}
//减法
Complex operator-(Complex &c1,Complex &c2)
{
    return Complex(c1.real-c2.real,c1.imag-c2.imag);
}
Complex operator-(double d,Complex &c1)
{
    Complex c(d,0);
    return c-c1;
}
Complex operator-(Complex &c1,double d)
{
    Complex c(d,0);
    return c1-c;
}
//乘法
Complex operator*(Complex &c1,Complex &c2)
{
    return Complex(c1.real*c2.real,c1.imag*c2.imag);
}
Complex operator*(double d,Complex &c1)
{
    Complex c(d,0);
    return c*c1;
}
Complex operator*(Complex &c1,double d)
{
    Complex c(d,0);
    return c*c1;
}
//除法
Complex operator/(Complex &c1,Complex &c2)
{
    return Complex(c1.real/c2.real,c1.imag/c2.imag);
}
Complex operator/(double d,Complex &c1)
{
    Complex c(d,0);
    return c/c1;
}
Complex operator/(Complex &c1,double d)
{
    Complex c(d,0);
    return c1/c;
}
void Complex::display()
{
    cout<<"("<<real<<","<<imag<<")"<<endl;
}
//下面定义用于测试的main()函数
//main函数偷的贺老师的~
int main()
{
    Complex c1(3,4),c2(5,-10),c3;
    double d=11;
    cout<<"c1=";
    c1.display();
    cout<<"c2=";
    c2.display();
    cout<<"d="<<d<<endl<<endl;
    cout<<"下面是重载运算符的计算结果: "<<endl;
    c3=c1+c2;
    cout<<"c1+c2=";
    c3.display();
    cout<<"c1+d=";
    (c1+d).display();
    cout<<"d+c1=";
    (d+c1).display();
    c3=c1-c2;
    cout<<"c1-c2=";
    c3.display();
    cout<<"c1-d=";
    (c1-d).display();
    cout<<"d-c1=";
    (d-c1).display();
    c3=c1*c2;
    cout<<"c1*c2=";
    c3.display();
    cout<<"c1*d=";
    (c1*d).display();
    cout<<"d*c1=";
    (d*c1).display();
    c3=c1/c2;
    cout<<"c1/c2=";
    c3.display();
    cout<<"c1/d=";
    (c1/d).display();
    cout<<"d/c1=";
    (d/c1).display();
    return 0;
}