c++: 复数类

#include<iostream>
using namespace std;

class complex
{
private:
   double real;
   double imaginary ;
public:
    complex():real(0),imaginary(0){}
    complex(double x,double y):real(x),imaginary(y){}
    void operator = (const complex&c){
        real=c.real;
        imaginary=c.imaginary;
    }
    ~complex(){}
    complex operator- () {
        return complex(-real,-imaginary);
    }
    complex operator+(const complex&c){
        complex com;
        com.real=real+c.real;
        com.imaginary=imaginary+c.imaginary;
        return com;
    }// 定义复数加法
    complex operator-(const complex&c){
        complex com;
        com.real = real - c.real;
        com.imaginary = imaginary - c.imaginary;
        return com;
    }//定义复数减法
    complex operator*(const complex&c){
        complex com ;
        com.real = real*c.real - imaginary*c.imaginary;
        com.imaginary = real*c.imaginary + imaginary*c.real;
        return com;
    }// 定义复数除法
    complex operator/(const complex&c){
        complex com;
        double denominator = c.real*c.real + c.imaginary*c.imaginary;
        com.real = (real*c.real + imaginary*c.imaginary)/denominator;
        com.imaginary = (imaginary*c.real-real*c.imaginary)/denominator;
        return com;
    }

    /*习惯上人们是使用 cin>> 和 cout<< 的，得使用友元函数来重载运算符，
    如果使用成员函数来重载会出现 d1<<cout; 这种不自然的代码*/
    friend ostream &operator<<( ostream &output, const complex &c ){ 
         output <<"( "<< c.real<<" ," <<c.imaginary<<" i )";
         return output;            
    }//输出运算符重载
    friend istream &operator>>( istream  &input, complex &c ){ 
         input >> c.real >> c.imaginary;
         return input;            
    }//输入运算符重载
};

int main(){
    complex a(4,6),b(2,-1);
    cout<<a<<" + "<<b<<" = "<<a+b<<endl;
    cout<<a<<" - "<<b<<" = "<<a-b<<endl;
    cout<<a<<" * "<<b<<" = "<<a*b<<endl;
    cout<<a<<" / "<<b<<" = "<<a/b<<endl;
    return 0;
}

输出

( 4 ,6 i ) + ( 2 ,-1 i ) = ( 6 ,5 i )
( 4 ,6 i ) - ( 2 ,-1 i ) = ( 2 ,7 i )
( 4 ,6 i ) * ( 2 ,-1 i ) = ( 14 ,8 i )
( 4 ,6 i ) / ( 2 ,-1 i ) = ( 0.4 ,3.2 i )