Cpp-learning/运算符重载1/3、递增运算符重载.cpp

//4.5.3  递增运算符重载

//作用：通过重载递增运算符，实现自己的整形数据

#if(0)


#include <iostream>

class MyInteger
{
	friend std::ostream& operator<<(std::ostream& cout, MyInteger myint); 

public:
	MyInteger()
	{
		m_Num = 0;
	}
	//重载前置++运算符   返回引用为了一直对一个数据进行递增操作
	MyInteger& operator++()
	{
		//先进行++运算
		m_Num++;

		//再将自身做返回
		return *this;
	}

	//重载后置++运算符
	//void operator++(int)    int代表的是一个占位参数  可以用于区分前置和后置递增
	MyInteger operator++(int)
	{
		//先    记录当时结果
		MyInteger temp = *this;

		//后    递增
		m_Num++;

		//最后将记录结果做返回
		return temp;

	}

private:
	int m_Num;

};

//重载<<运算符
std::ostream& operator<<(std::ostream&cout , MyInteger myint)
{
	std::cout << myint.m_Num;
	return cout;
}

void test01()
{
	MyInteger myint;

	std::cout << ++(++myint) << std::endl;
	std::cout << myint << std::endl;
}

void test02()
{
	MyInteger myint;

	std::cout << myint++ << std::endl;
	std::cout << myint << std::endl;
}


int main()
{

	//test01();
	test02();

	//int a = 0;
	//std::cout << ++(++a) << std::endl;
	//std::cout << a << std::endl;

	system("pause");

	return 0;

}

#endif

//总结 ：前置递增返回的是引用，后置递增返回的是值