C++ //赋值运算符重载 =

//赋值运算符重载 =
#include <iostream>
#include <string>
using namespace std;

//赋值运算符的重载
class Person
{
public:

    Person(int age)
    {
        m_Age = new int(age);
    }
    ~Person()
    {
        if (m_Age != NULL)
        {
            delete m_Age;
            m_Age = NULL;
        }
    }
    //重载 赋值运算符
    Person& operator= (Person& p)
    {
        //编译器是提供浅拷贝
        //m_Age = p.m_Age;

        //应该先判断是否有属性再堆区，如果有先释放干净 然后再深拷贝
        if (m_Age != NULL)
        {
            delete m_Age;
            m_Age = NULL;
        }

        //深拷贝
        m_Age = new int(*p.m_Age);
        //返回对象本身

        return *this;

    }

    int  *m_Age;
};

void test01()
{
    Person p1(18);

    Person p2(20);

    Person p3(30);

    p1 = p2 = p3;

    //p2 = p1; //赋值操作

    cout << *p1.m_Age << endl;
    cout << *p2.m_Age << endl;
    cout << *p3.m_Age << endl;
}
int main()
{
    test01();


    int a = 10;
    int b = 20;
    int c = 30;

    a = b = c;

    cout << "a = " << a << endl;
    cout << "b = " << b << endl;
    cout << "c = " << c << endl;
}