////   This file contains the C++ code from Program 6.15 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_15.cpp//QueueAsArray::QueueAsArray (unsigned int size) :    array (size),    head (0),    tail (size - 1U)    {}void QueueAsArray::Purge (){    if (IsOwner ())    {	for (unsigned int i = 0; i < count; ++i)	{	    delete array [head];	    if (++head == array.Length ())		head = 0;	}    }    count = 0;}QueueAsArray::~QueueAsArray ()    { Purge (); }