实现复数类中的运算符重载（含有double类型）

/*
* 作    者： 霍雨佳
* 完成日期：2014 年4月15日
* 版 本 号：v1.0
* 问题描述：实现复数类中的运算符重载。
* 样例输入：
* 样例输出：
* 问题分析：一个定义完整的类，是可以当作独立的产品发布，成为众多项目中的“基础工程”，这样的类在方案二的基础上，扩展+、-、*、/运算符的功能，
*           使之能与double型数据进行运算。设Complex c; double d; c+d和d+c的结果为“将d视为实部为d的复数同c相加”，其他-、*、/运算符类似。
*/
#include 

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-(Complex &c1,Complex &c2);
    friend Complex operator*(Complex &c1,Complex &c2);
    friend Complex operator/(Complex &c1,Complex &c2);
    friend Complex operator+(Complex &c1,double c);
    friend Complex operator-(Complex &c1,double c);
    friend Complex operator*(Complex &c1,double c);
    friend Complex operator/(Complex &c1,double c);
    friend Complex operator+(double c,Complex &c1);
    friend Complex operator-(double c,Complex &c1);
    friend Complex operator*(double c,Complex &c1);
    friend Complex operator/(double c,Complex &c1);
    void display();
private:
    double real;
    double imag;
};
Complex operator+(Complex &c1,Complex &c2)
{
    return  Complex(c2.real+c1.real,c2.imag+c1.imag);
}
Complex operator-(Complex &c1,Complex &c2)
{
    return  Complex(c2.real-c1.real,c2.imag-c1.imag);
}
Complex operator*(Complex &c1,Complex &c2)
{
    return  Complex((c2.real*c1.real-c1.imag*c2.imag),(c1.real*c2.imag+c1.imag*c2.real));
}
Complex operator/(Complex &c1,Complex &c2)
{
    Complex c;
    c.real=((c2.real*c1.real+c1.imag*c2.imag)/((c2.real*c2.real)+(c2.imag*c2.imag)));
    c.imag=((c1.real*c2.imag-c1.imag*c2.real)/((c2.real*c2.real)+(c2.imag*c2.imag)));
    return c;
}
Complex operator+(Complex &c1,double c)
{
    return  Complex(c+c1.real,c1.imag);
}
Complex operator-(Complex &c1,double c)
{
    return  Complex(c-c1.real,-c1.imag);
}
Complex operator*(Complex &c1,double c)
{
    return  Complex((c*c1.real),(c1.imag*c));
}
Complex operator/(Complex &c1,double c)
{
    Complex c7;
    c7.real=((c*c1.real)/(c*c));
    c7.imag=-((c1.imag*c)/(c*c));
    return c7;
}
Complex operator+(double c,Complex &c1)
{
    return  Complex(c+c1.real,c1.imag);
}
Complex operator-(double c,Complex &c1)
{
    return  Complex(c1.real-c,c1.imag);
}
Complex operator*(double c,Complex &c1)
{
    return  Complex((c*c1.real),(c1.imag*c));
}
Complex operator/(double c,Complex &c2)
{
    Complex c7;
    c7.real=((c2.real*c)/((c2.real*c2.real)+(c2.imag*c2.imag)));
    c7.imag=((c*c2.imag)/((c2.real*c2.real)+(c2.imag*c2.imag)));
    return c7;
}
void Complex::display()
{
    cout<<"("<
 
  
  因为不适用交换律，所以敲了好多代码，但自己有只是在重复代码的赶脚……