////   This file contains the C++ code from Program 6.22 of//   "Data Structures and Algorithms//    with Object-Oriented Design Patterns in C++"//   by Bruno R. Preiss.////   Copyright (c) 1998 by Bruno R. Preiss, P.Eng.  All rights reserved.////   http://www.pads.uwaterloo.ca/Bruno.Preiss/books/opus4/programs/pgm06_22.cpp//void Deque::Enqueue (Object& object)    { EnqueueTail (object); }Object& Deque::Dequeue ()    { return DequeueHead (); }