using System;
using System.IO;
class First {}
class Second : First {}
class C : First {}
class RTTIDemo
{
	
	public static void Main() 
	{
		First a  = new First();
		Second b = new Second();
		if( a is First ) 
			Console.WriteLine ( "a is a First" );
		if( b is First) 
			Console.WriteLine( "b is a First because it is deriived from First" );
		if(b is Second) 
			Console.WriteLine( "b is Second" );
		if(a is object) 
			Console.WriteLine("a is an Object");

		C c = new C();
		c = a as C;              

		if(c == null) 
			Console.WriteLine( "Cast c = (C) a is not allowed." );
		else 
			Console.WriteLine( "Cast c = (C)a is allowed" );

		Type t = typeof( StreamReader );
		Console.WriteLine( t.FullName );

		if ( t.IsClass ) 
			Console.WriteLine( "Is a class" );
		if( t.IsAbstract ) 
			Console.WriteLine( "Is abstract." );
		else 
			Console.WriteLine( "Is concrete." );

		Console.Read();
	}
}