struct Base {
	int result;
	virtual void Add(Ctrl &) { result = 1; }
};

struct Midd : public Base{
	//virtual void Add(Ctrl &) { result = 2; } //EITHER this, virtual or not, no metter
	using Base::Add; //OR this, saves compilation preserving complete Add overloads pool for compiler
	void Add(int)			{ result = 4; }
	void Nothing()   { result = 10; }
};

GUI_APP_MAIN
{
	Label l;
	Midd md;
	
	//option 1: << desired >>
	void (Midd::* mfp)(Ctrl &) = &Midd::Add; //problems even if Mid, not only Top
	(md.*mfp)(l);
}