// inherit17.cpp  		By: Aiman Hanna -  ©1993-2005 Aiman Hanna

// This program illustrates more on inheritance and virtual functions 
// in the inheritance tree. The program deals with the problem introduced
// in inherit16.cpp. You should notice the output carefully. 

#include <iostream.h>

class A
{
	public:
		void fun() {cout << "A" << endl;};
	
};

class B : public A 
{
	public:
		virtual void fun() {cout << "B" << endl;}; // The function is made virtual here
	
};

class C : public B 
{
	public:
		 void fun() {cout << "C" << endl;};

};

int main()
{

	
	B *b1;
	b1 = new C();
	b1 -> fun();
	delete b1;
	

	A *a1;
	a1 = new C();   // since the function is not virtual, the pointer is actually 
					// made to A (at least from the compiler point-of-view)
	
	a1 -> fun();	// this will call fun() defined in A .. expected!!

	delete (C*)a1;  	// now you can NOT just delete a1; since this will 
      // attempt to delete  an A object, which is not the case. 
      // Such command will result in nothing but run-time error. 

	return 0;
}

// Compilation Successful
/* Output
C
A
*/