//

// Created by zing on 6/5/2020.

//

#include <iostream>

using namespace std;

class Person {

public:

int m_A;

int m_B;

Person() {};

Person(int a, int b) {

this->m_A = a;

this->m_B = b;

}

//成员函数实现 + 号运算符重载

Person operator+(const Person &p) {

Person temp;

temp.m_A = this->m_A + p.m_A;

temp.m_B = this->m_B + p.m_B;

return temp;

}

};

//全局函数实现 + 号运算符重载

//Person operator+(const Person& p1, const Person& p2) {

// Person temp(0, 0);

// temp.m_A = p1.m_A + p2.m_A;

// temp.m_B = p1.m_B + p2.m_B;

// return temp;

//}

//运算符重载 可以发生函数重载

Person operator+(const Person &p2, int val) {

Person temp;

temp.m_A = p2.m_A + val;

temp.m_B = p2.m_B + val;

return temp;

}

void test() {

Person p1(10, 10);

Person p2(20, 20);

//成员函数方式

Person p3 = p2 + p1; //相当于 p2.operaor+(p1)

cout << "mA:" << p3.m_A << " mB:" << p3.m_B << endl;

Person p4 = p3 + 10; //相当于 operator+(p3,10)

cout << "mA:" << p4.m_A << " mB:" << p4.m_B << endl;

}

class Person2 {

friend ostream &operator<<(ostream &out, Person2 &p);

public:

Person2(int a, int b) {

this->m_A = a;

this->m_B = b;

}

//成员函数 实现不了 p << cout 不是我们想要的效果

//void operator<<(Person& p){

//}

private:

int m_A;

int m_B;

};

//全局函数实现左移重载

//ostream对象只能有一个

ostream &operator<<(ostream &out, Person2 &p) {

out << "a:" << p.m_A << " b:" << p.m_B;

return out;

}

void test2() {

Person2 p1(10, 20);

cout << p1 << "hello world" << endl; //链式编程

}

class MyInteger {

friend ostream &operator<<(ostream &out, MyInteger myint);

public:

MyInteger() {

m_Num = 0;

}

//前置++

MyInteger &operator++() {

//先++

m_Num++;

//再返回

return *this;

}

//后置++

MyInteger operator++(int) {

//先返回

MyInteger temp = *this; //记录当前本身的值，然后让本身的值加1，但是返回的是以前的值，达到先返回后++；

m_Num++;

return temp;

}

private:

int m_Num;

};

ostream &operator<<(ostream &out, MyInteger myint) {

out << myint.m_Num;

return out;

}

//前置++ 先++ 再返回

void test01() {

MyInteger myInt;

cout << ++myInt << endl;

cout << myInt << endl;

}

//后置++ 先返回 再++

void test02() {

MyInteger myInt;

cout << myInt++ << endl;

cout << myInt << endl;

}

int main() {

test();

test2();

test01();

return 0;

}