#ifndef _LIST
#define _LIST

template <class T>
class List;

template <class T>
class ListNode
{
friend class List<T>;

private:
	T data;
	ListNode<T> *next;

public:
	ListNode(T d);
};

template <class T>
class List
{
private:
	ListNode<T> *head;

public:
	List();
	int  Length() const;
	bool Member(const T& d);
	void Insert(const T& d);
	bool Delete(const T& d);
	void Output(ostream& out) const;
};

// overload <<
template <class T>
ostream& operator<<(ostream& out, const List<T>& l)
{
	l.Output(out);
	return out;
}

#endif