////   This file contains the C++ code from Program 6.25 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_25.cpp//Object& DequeAsArray::Tail () const{    if (count == 0)	throw domain_error ("deque is empty");    return *array [tail];}void DequeAsArray::EnqueueHead (Object& object){    if (count == array.Length ())	throw domain_error ("deque is full");    if (head-- == 0)	head = array.Length () - 1U;    array [head] = &object;    ++count;}Object& DequeAsArray::DequeueTail (){    if (count == 0)	throw domain_error ("deque is empty");    Object& result = *array [tail];    if (tail-- == 0)	tail = array.Length () - 1U;    --count;    return result;}