c++之递增运算符重载

#include<iostream>
using namespace std;

class MyInteger {
    friend ostream& operator<<(ostream& cout, MyInteger myInteger);
public:
    MyInteger() {
        num = 0;
    }
    //重载++i运算符
    //返回引用是为了对同一个数据进行递增操作
    MyInteger & operator++() {
        num++;
        return *this;
    }
    //重载i++运算符，int是占位符,后置递增要返回值
    MyInteger operator++(int) {
        //先记录当时结果
        MyInteger tmp = *this;
        //后递增
        num++;
        //再返回记录的结果
        return tmp;
    }
private:
    int num;
};

ostream & operator<<(ostream &cout,MyInteger myInteger) {
    cout << "num=" << myInteger.num;
    return cout;
}
void test() {
    MyInteger myInteger;
    cout << ++(++myInteger)<<endl;
    cout << myInteger << endl;
}

void test2() {
    MyInteger myInteger;
    cout << myInteger++ << endl;
    cout << myInteger << endl;
}

int main() {
    test2();
    system("pause");
    return 0;
}

 MyInteger & operator++() {
        num++;
        return *this;
    }