#include <stdio.h>

class A
{
public:
	typedef void (A::*virt_method_ptr)();

	virt_method_ptr m_pMethod;

public:
	A()
	{
		m_pMethod = &A::func1;
	}

	void call_method_through_ptr()
	{
		(this->*m_pMethod)();
	}

	virtual void func1()
	{
		puts( "called A::func1()" );
	}

	virtual void func2()
	{
		puts( "called A::func2()" );
	}

	virtual void func3()
	{
		puts( "called A::func3()" );
	}
};

class B : public A
{
public:
	int nTestPrintMe;

public: 
	B( int n )
	{
		m_pMethod = reinterpret_cast<virt_method_ptr>(&B::func4);
		nTestPrintMe = n;
	}

	virtual void func3()
	{
		puts( "called B::func3()" );
	}

	virtual void func4()
	{
		printf( "called B::func4( %d ) \n", nTestPrintMe );
	}
};

int main ()
{
	A *o = new B( 10 );

	o->call_method_through_ptr();

	o->m_pMethod = &A::func1;
	o->call_method_through_ptr();

	o->m_pMethod = &A::func2;
	o->call_method_through_ptr();

	o->m_pMethod = &A::func3;
	o->call_method_through_ptr();

	o->m_pMethod = reinterpret_cast<A::virt_method_ptr>(&B::func4);
	o->call_method_through_ptr();

	return 0;
}