For use with CMSC-341, Spring 99,  Project 2

Here is the definition of the LinkedList class. 

Copy it to your LinkedList.H file. 

Remember:
 -- implement the inline method(s)
 -- guard the file
 -- complete the documentation
------------------------------------------------

// forward references for template classes
template <class Type> class LinkedList;
template <class Type> class LinkedListIterator;

/*
   A circular, doubly-linked List.
   Author: Thomas Anastasio
   Version: 28 February 1999
*/
template <class T>
class LinkedList : public List<T>
{
  friend class LinkedListIterator<T>;

private:
  DlNode<T>* _tail; // _tail->next is the head of the list
protected:
  inline DlNode<T>* Tail(); // tail node accessor
  inline void SetTail(DlNode<T>* n);
public:
  LinkedList();
  LinkedList(const LinkedList<T> &);
  virtual ~LinkedList();
  char * ToString();
  virtual bool Insert(const T& x, int pos);
  virtual bool Append(const T& x);
  virtual T& Retrieve(int pos);
  virtual bool Delete(int pos);
  virtual void MakeEmpty();  
  virtual Iterator<T> * GetIterator();
  virtual Iterator<T> * GetReverseIterator();
};