////   This file contains the C++ code from Program 13.9 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/pgm13_09.cpp//void DoublyLinkedPool::Release (void* arg){    Block& block = *reinterpret_cast<Block*> (	reinterpret_cast<Header*> (arg) - 1U);    if (&block < pool || &block >= pool + numberOfBlocks)	throw invalid_argument ("invalid block");        block.status = free;    InsertAfter (sentinel, block);}