The Generic List Class

class List {
public:
		// constructor
	List() : firstElement(0) { }

		// operations
	void Add(Link * n)
		{ n->next = firstElement; firstElement = n; }

	int isEmpty()
		{ return firstElement == 0; }

	Link * First();
		{ return firstElement; }

	void RemoveFirst();
		{ Link * p = firstElement; 
		  firstElement = firstElement-> next;
		  delete p; }

	int  Includes(Link * n)
		{ for (Link * p = firstElement; p; p = p->next)
			if (*p == *n) return 1;
		  return 0; }

private:
		// data field
	Link * firstElement;
};

class Link {
public:
		// constructors
	Link () : next(0) { }
	Link (Link * n) : next(n) { }

		// operations
	virtual int operator == (Link *) = 0;

		// data field
	Link * next;
};

Intro OOP, Chapter 15, Slide 7