c++中重载自增时 cout与++出错

Question

完整代码如下：

#include <iostream>
using namespace std;

class Person3 {
    friend ostream& operator<<(ostream& cout, Person3& p1);
public:


    Person3(int a, int b) :m_A(a), m_B(b) {
    }

    Person3& operator++() { 
        this->m_A += 10;
        this->m_B += 10;
        return *this;
    }

    //返回值
    const Person3 operator++(int) { 
        Person3 temp = *this;
        this->m_A += 10;
        this->m_B += 10;
        return temp;
    }

private:
    int m_A;
    int m_B;
};


//运算符重载函数的重载
ostream& operator<<(ostream& cout, Person3& p1) {
    cout << "m_A = " << p1.m_A << "  m_b= " << p1.m_B;
    return cout;
}

void test02() {
    Person3 p1(10, 10);
    Person3 p2(50, 50);
    cout << p1 << endl;
    cout << ++(++p1) << endl;
    p2++;
    cout << p2 << endl;
    cout << p2++ << endl;
}


int main() {
    test02();

    return 0;
}

Answer 1

operator<<第二个参数改为const Person3&，因为后缀++返回的类型是const Person3，不能传递给Person3&类型