//================================================================
// This module provides class Queue, a kind of first-in-first-out
// queue.  The constructor creates an empty queue.  Objects of
// class Queue have the following capabilities.
//
// q.insert(x)    Insert object x at the back of queue q.
//
// q.remove(x)    Remove the object at the front of queue q and store
//                the object into variable x.  An attempt to remove
//                an object from an empty queue will cause the program
//                to stop.
//
// q.isEmpty()    Return true if q is empty, false if not.
//
// q.length()     Return the length of queue q.
//
// q.print()      Print all of the objects in queue q, from
//                front to back.
//================================================================

#ifndef QUEUE_H
#define QUEUE_H

#include "simobject.h"

class Queue
{
public:
  Queue();
  void insert(SimObject* obj);
  void remove(SimObject*& obj);
  bool isEmpty() const;
  int length() const;
  void print() const;

private:
  struct QCell;

  QCell* ptr;
  int len;
  void insert(QCell*& p, SimObject* obj);
};

#endif