////   This file contains the C++ code from Program 4.22 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/pgm04_22.cpp//template <class T>class Matrix : public Array2D<T>{public:    Matrix (unsigned int, unsigned int);    Matrix operator * (Matrix const&) const;    Matrix operator + (Matrix const&) const;};