date.h

一个指针的例子,C++语言,我在初学C++时写的,大家请多指教

#pragma once
#include <string>

class date
{
public:
	date& add_month(int m);
	date& add_year(int y);

	date(int,int,int);
	date():_year(1999),_month(12),_day(31){	};
	virtual ~date(void);

	std::string string_rep();
	static date& today();	
	static date& chang_today(int newYear,int newMonth,int newDay);
	static void show_date(date&);


private:
	static date now;
	int _year,_month,_day;	
	
};