demo_operator_04_a.cpp

对于一个初涉VC＋＋的人来书

//************************************************

# include <iostream.h>

class Increase
{
public:
	Increase(int x):value(x){}
	Increase & operator ++();  //前增量
	Increase operator ++(int); //后增量
	void display() { cout<<"The value is: "<<value<<endl; }
private:
	int value;
};

Increase & Increase::operator ++() //前增量返回引用
{
	++value;       //先增量
	return *this;  //再返回原对象
}

Increase Increase::operator ++(int) //后增量返回值
{
	Increase temp(*this); //临时对象存放原有对象值
	value++;              //原有对象增量修改
	return temp;          //返回原有对象值
}

void main()
{
	Increase n(20);

	n.display();
	(n++).display();
	n.display();

	++n;
	n.display();
	++(++n);
	n.display();

	(n++)++;
	n.display();
}