c15_06.cpp

这是编程之道C-C++中的源代码,很简练,可以用于相关教学和重新熟悉C-C++时使用

//重载后缀和前缀自增运算符
#include <iostream >
using namespace std;

class CCounter
{
public:
	CCounter():m_val(0){ }
	~CCounter(){}

	unsigned GetVal()const { return m_val; }
	void SetVal(unsigned x) {m_val = x; }
	void Increment() { ++m_val; }
	const CCounter& operator++ ();		//重载前缀++运算符
	const CCounter operator++ (int);	/*重载后缀++运算符，带一个整型参数，
																表示是后缀运算符*/
private:
	unsigned m_val;
};

const CCounter& CCounter::operator++()
{
	++m_val;
	return *this;
}

const CCounter CCounter::operator++(int)
{
	CCounter temp;
	temp.m_val = m_val;		//将对象原有的值保存到临时对象中
	++m_val;				//自增对象的值
	return temp;			//返回临时对象
}

int main()
{
	CCounter counter;
	cout << "counter的值是：" << counter.GetVal() << endl;
	counter.Increment();
	cout << "调用自增函数之后，";
	cout << "counter的值是：" << counter.GetVal() << endl;
	++counter;
	cout<< "使用自增运算符++之后,";
	cout << "counter的值是：" << counter.GetVal() << endl;
	CCounter counter2 = ++counter;
	cout << "counter2的值是：" << counter2.GetVal() << endl;
	cout << "counter的值是：" << counter.GetVal() << endl;
	counter2 = counter++;
	cout << "counter2的值是：" << counter2.GetVal() << endl;
	cout << "counter的值是：" << counter.GetVal() << endl;

	return 0;
}