////   This file contains the C++ code from Program 6.26 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_26.cpp//class DequeAsLinkedList : public Deque, public QueueAsLinkedList{public:    DequeAsLinkedList ();    // ...};