实现++的重载函数

#include<iostream>
using namespace std;
//运算符的重载:
class People
{
	//将全局函数设置成友元:
	friend ostream& operator<<(ostream& out, People peo);
	friend istream& operator>>(istream& in, People& peo);
private:
	int age;
	string name;
	float score;
public:
	People() {}
	People(int age, string name, float score) :age(age), name(name), score(score) {}
	~People() {}
	//用成员函数实现+运算符的重载:
	People operator+(People& p)
	{
		People tmp;
		tmp.age = age + p.age;
		tmp.name = name + p.name;
		tmp.score = score + p.score;
		return tmp;
	}
	//用成员函数实现==运算符:
	bool operator==(People& p)
	{
		if (age == p.age && name == p.name && score == p.score)
			return true;
		return false;
	}
	//实现后置++的重载函数;
	People operator++(int)  //占位参数
	{
		People old = *this;
		age++;
		name = name + name;
		score++;
		return old;
	}
	People operator++()
	{
		age++;
		name = name + name;
		score++;
		return *this;
	}
};
//重载输出操作符:
ostream& operator<<(ostream& out, People peo)
{
	out << peo.age << ' ' << peo.name << ' ' << peo.score << endl;
	return out;
}

istream& operator>>(istream& in, People& peo)
{
	in >> peo.age >> peo.name >> peo.score;
	return in;
}


int main()
{
	People John(10,"John",88);
	People Danny;

#if 0
	//cin >> John >> Danny;
	cout << John << Danny;
	//使用成员函数实现+的运算符重载:
	cout << John.operator+(Danny)<<endl;
	if (John == Danny)
	{
		cout << "相等" << endl;
	}
	else
	{
		cout << "不相等" << endl;
	}
#endif
	//实现++自增的重载函数:
	//实现后置++
	Danny = John++;
	Danny = ++John;
	cout << Danny << John << endl;
	return 0;
}