C++运算符重载 加号运算

c++运算符重载功能可以，将平常使用的运算符赋予新的功能，其关键字为 operator ，
格式为：
类型名 operator 运算符（ 变量类型 变量，变量类型 变量）

示例1.在全局变量使用运算符重载

#include<iostream>
using namespace std;;

class person
{
// public:
    // person operator+(person & p)
    // {
    //     person temp;
    //     temp.m_a = this->m_a + p.m_a;
    //     temp.m_b = this->m_b + p.m_b;
    // }
public:
    int m_a;
    int m_b;    
};
person operator+(person &p1, person &p2)
{
    person temp;
    temp.m_a = p1.m_a + p2.m_a;
    temp.m_b = p1.m_b + p2.m_b;
    return temp;
}
int main()
{
    person p1;
    p1.m_a = 20;
    p1.m_b = 10;
    person p2;
    p2.m_a = 10;
    p2.m_b = 20;
    person p3 = p1 + p2;
    cout << p3.m_a << endl;
}

示例2 在类中使用运算符重载

#include<iostream>
using namespace std;;

class person
{
public:
    person operator+(person & p)
    {
        person temp;
        temp.m_a = this->m_a + p.m_a;
        temp.m_b = this->m_b + p.m_b;
    }
public:
    int m_a;
    int m_b;    
};
// person operator+(person &p1, person &p2)
// {
//     person temp;
//     temp.m_a = p1.m_a + p2.m_a;
//     temp.m_b = p1.m_b + p2.m_b;
//     return temp;
// }
int main()
{
    person p1;
    p1.m_a = 20;
    p1.m_b = 10;
    person p2;
    p2.m_a = 10;
    p2.m_b = 20;
    person p3 = p1 + p2;
    cout << p3.m_a << endl;
}