谭浩强c++第三版9-10

#include<iostream>
using namespace std;

//将例9-13程序中display不放在time类中而作为普通函数

class Date;
class Time
{
public:
	Time(int h,int m,int s):hour(h),minute(m),sec(s){}
	friend void display(Date&, Time&);
private:
	int hour;
	int minute;
	int sec;
};

class Date
{
public:
	Date(int y,int mo,int d):year(y),month(mo),day(d){}
	friend void display(Date&,Time&);
private:
	int year;
	int month;
	int day;
};

void display(Date& d1,Time &t1)
{
	cout << d1.year << "/" << d1.month << "/"<< d1.day << endl;
	cout << t1.hour << "/" << t1.minute << "/" << t1.sec << endl;
}

int main()
{
	Time t(10, 13, 56);
	Date d(12, 25, 2004);
	display(d,t);
	return 0;
}