C++ 后置运算符重载 =

#include <iostream>

using namespace std;

class num
{
public:
	num(int m){n = m;cout<<"num("<<n<<")"<<endl;}
	~num(){cout<<"~num()"<<endl;}
	num(num &m){n = m.n;cout<<"num(&)"<<endl;}
	int get(){return n;}
	void set(int a){ n = a;}
	num& operator=(num &m){cout<<"****************"<<endl;n = m.n; return *this;}

private:
	int n;
};

int main()
{
	num m1(10);
	num m2(90);
	cout<<"after create m1, m2"<<endl;
	cout<<"m1->n = "<<m1.get()<<"   m2->n = "<<m2.get()<<endl;
	cout<<"before   set m2 = m1"<<endl;
	m2 = m1;
	cout<<"after    set m2 = m1"<<endl;
	cout<<"m1->n = "<<m1.get()<<"   m2->n = "<<m2.get()<<endl;
	cout<<"change m1 value"<<endl;
	m1.set(88);
	cout<<"m1->n = "<<m1.get()<<"   m2->n = "<<m2.get()<<endl;
	cout<<"main -over"<<endl;
	return 0;
}

result:

num(10)
num(90)
after create m1, m2
m1->n = 10   m2->n = 90
before   set m2 = m1
****************
after    set m2 = m1
m1->n = 10   m2->n = 10
change m1 value
m1->n = 88   m2->n = 10
main -over
~num()
~num()