//--------------------------------------------------------------------
//
//  Laboratory 6                                          queuelnk.h
//
//  Class declarations for the linked list implementation of the
//  Queue ADT
//
//--------------------------------------------------------------------

template < class QE >
class QueueNode               // Facilitator class for the Queue class
{
  private:

    // Constructor
    QueueNode ( const QE &elem, QueueNode *nextPtr );

    // Data members
    QE element;          // Queue element
    QueueNode *next;     // Pointer to the next element

  friend class Queue<QE>;
};

//--------------------------------------------------------------------

template < class QE >
class Queue
{
  public:

    // Constructor
    Queue ( int ignored = 0 );

    // Destructor
    ~Queue ();

    // Queue manipulation operations
    void enqueue ( const QE &newElement );    // Enqueue element
    QE dequeue ();                            // Dequeue element
    void clear ();                            // Clear queue

    // Queue status operations
    int empty () const;                       // Queue is empty
    int full () const;                        // Queue is full

    // Output the queue structure -- used in testing/debugging
    void showStructure () const;

  private:

    // Data members
    QueueNode<QE> *front,   // Pointer to the front element
                  *rear;    // Pointer to the rear element
};