////   This file contains the C++ code from Program 8.21 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/pgm08_21.cpp//void OpenScatterTable::Withdraw (Object& object){    if (count == 0)	throw domain_error ("scatter table is empty");    unsigned int const offset = FindInstance (object);    if (offset == length)	throw invalid_argument ("object not found");    array [offset].state = Entry::deleted;    array [offset].object = 0;    --count;}