赋值运算符重载

 赋值运算符重载用于解决赋值操作的浅拷贝问题； 

#include
#include
using namespace std;
class Person
{
public:
	int *m_age;
	//构建函数
	Person(int age)
	{
		//将年龄数据开辟到堆区；
		m_age = new int(age);
	}
	//重载赋值运算符
	Person& operator=(Person& p)
	{
		if (m_age)
		{
			delete m_age;
			m_age = NULL;
		}
		//编译器提供的拷贝；浅拷贝
		//m_age=p.m_age;
		//深拷贝；
		m_age = new int(*p.m_age);
		//返回自身，实现链式编程；
		return *this;
	}

	//析构函数
	~Person()
	{
		if (m_age)
		{
			delete m_age;
			m_age = NULL;
		}
	}
};


int main() 
{
	Person p1(18);
	Person p2(20);
	Person p3(30);
	//赋值
	p1 = p2=p3;

	cout << *p1.m_age << endl;
	cout << *p2.m_age << endl;
	cout << *p3.m_age << endl;
	system("pause"); 
	return 0;
}