C++笔记之 运算符重载

//格式
//函数类型 operator 运算符（形参表）
//{
// 函数体；
//}

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#include<iostream>using namespace std;class Complex{public :double m_real;double m_imag;Complex ()    {}Complex (double m_real,double m_imag){this->m_imag=m_imag;this->m_real=m_real;}void show(){cout<< m_real <<"+"<<m_imag<<"i" <<endl;}Complex operator-(Complex &c)    //&表示引用    //给一个变量起别名    //使用引用可以减少内存的消耗和赋值的过程{return Complex (this->m_real-c.m_real,this->m_imag- c.m_imag);}};//cout<<a<<b//1.cout = cout.operator(a)//2.cout = cout.operator(b)//保证所有的cout为同一对象//入参又采用引用 保证是cout全局变量的别名//返回值依旧使用引用 保证等的左侧依旧是原本cout 不发生改变ostream& operator<<(ostream &out,Complex &c)// ***输出流的重载***{    out<< c.m_real << "+" << c.m_imag <<"i" <<endl;    return out;};istream& operator>>(istream &in,Complex &c)//**输入流的重载**{    in>> c.m_real >> c.m_imag;    return in;};int main(){Complex c1(10.0,5.0);Complex c2(5.0,10.0);Complex c3;cin >>c3; //Complex c3 = c1 + c2;//c1 + c2 相当于调用                    //c1为this 所指向的对象                    //c2位传入的参数//Complex c3=c1-c2;c3.show();//cout<<c1<<c2; return 0;}//可以用作重载的运算符://算术运算符：+,-,*,/,%,++,--;//位操作运算符：&,|,~,^,＜＜,＞＞//逻辑运算符：!,&&,||;//比较运算符：＜,＞,＞=,＜=,==,!=;//赋值运算符：=,+=,-=,*=,/=,%=,&=,|=,^=,＜＜=,＞＞=;//其他运算符：[],(),-＞,,(逗号运算符),new,delete,new[],delete[],-＞*。//下列运算符不允许重载：//.  .*  ::   ?: