////   This file contains the C++ code from Program 6.4 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_04.cpp//void StackAsArray::Push (Object& object){    if (count == array.Length ())	throw domain_error ("stack is full");    array [count++] = &object;}Object& StackAsArray::Pop (){    if (count == 0)	throw domain_error ("stack is empty");    return *array [--count];}Object& StackAsArray::Top () const{    if (count == 0)	throw domain_error ("stack is empty");    return *array [count - 1U];}