cpp09.cpp

C++参考书

// Coded by plusir -- Dec.30.2002.
// Standard C++ Bible -- (P292-11-9)

#include <iostream>
using namespace std ;

class CustomDate
{
	public:
		CustomDate( void ) { } 
		CustomDate( int d, int y )
		{
			da = d ;
			yr = y ;
		}

		void display( void ) const
		{ cout << endl << yr << '-' << da ; }

		int da, yr ;
} ;

class Date
{
	public:
		Date( int m, int d, int y )
		{
			mo = m ;
			da = d ;
			yr = y ;
		}

		operator CustomDate( void )
		{
			static int dys[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } ;

			CustomDate cd( 0, yr ) ;
			for ( int i = 0; i < mo - 1; ++i )
				cd.da += dys[i] ;
			cd.da += da ;

			return cd ;
		}

	private:
		int mo ;
		int da ;
		int yr ;
} ;

class Tester
{
	public:
		explicit Tester( CustomDate c )
		{ cd = c ; }

		void display( void ) const
		{ cd.display() ; }

	private:
		CustomDate cd ;
} ;

void displayDate( CustomDate cd )
{
	cd.display() ;
}

CustomDate returnDate( void )
{
	Date dt( 10, 11, 88 ) ;
	return dt ;
}

int main()
{
	Date dt( 11, 17, 89 ) ;
	CustomDate cd ;

	cd = dt ;
	cd.display() ;

	displayDate( dt ) ;

	Tester ts( dt ) ;
	ts.display() ;

	cd = returnDate() ;
	cd.display() ;

	return 0 ;
}