How to get virtual functions to inherit?

[prestokeys]

#include <iostream>

using namespace std;

class A {
   	public:
   		int a;   	
     	A (): a(0) {} 
		virtual void f () {a = 111;}
		virtual ~A() {}
};

class B: public A {
	public:
    	int b;
    	B (): A(), b(0) {}
       	virtual void f() {b = 3;}
};


int main()
{
   	A andy;
   	cout << "andy created:" << endl;
	cout << "andy.a = " << andy.a << endl;  // 0
	B bob;
   	cout << "bob created:" << endl;
	cout << "bob.a = " << bob.a << endl;  // 0
	cout << "bob.b = " << bob.b << endl;  // 0
	cout << "andy.f() called:" << endl;
	andy.f();
	cout << "andy.a = " << andy.a << endl;  // 111
	bob.f();
	cout << "bob.f() called:" << endl;
	cout << "bob.a = " << bob.a << endl;  // 0 (NOT 111)
	cout << "bob.b = " << bob.b << endl;  // 3
	cin.get();
	return 0;
}

The same result occurs whether they are polymorphic or not. The behaviour I want is for the function f to change both the values of a and b when f is called on derived class B, i.e. I want f to both behave as it would for its parent class A and for B when called on B. How to achieve this without defining two separate functions, or pasting the entire code in A again? Of course, I actually have chains of classes with myriads of data members that I want this property for, especially since I'm constantly adding new data members (so updating the virtual functions to maintain this property is a headache, and easy to forget to do too).

[MatthewRock]

You don't need virtual keyword in derived class.

If you want to use polymorphism, you have to use pointers.

If you want to change two variables, just change them:

//in class B
void f() { b = 3; a = 111; }

optionally(untested, I may be wrong):

//in class B
void f() {A::f(); b = 3; }

[prestokeys]

-> void f() {A::f(); b = 3; }

Yes. That is the generic method I was seeking. It works. Thanks.