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// 
// StreamUtil.h 
// 
// Library: Foundation 
// Package: Streams 
// Module:  StreamUtil 
// 
// Stream implementation support. 
// 
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH. 
// and Contributors. 
// 
// SPDX-License-Identifier:	BSL-1.0 
// 
 
 
#ifndef Foundation_StreamUtil_INCLUDED 
#define Foundation_StreamUtil_INCLUDED 
 
 
#include "Poco/Foundation.h" 
 
 
// poco_ios_init 
// 
// This is a workaround for a bug in the Dinkumware 
// implementation of iostreams. 
// 
// Calling basic_ios::init() multiple times for the 
// same basic_ios instance results in a memory leak 
// caused by the ios' locale being allocated more than 
// once, each time overwriting the old pointer. 
// This usually occurs in the following scenario: 
// 
// class MyStreamBuf: public std::streambuf 
// { 
//     ... 
// }; 
// 
// class MyIOS: public virtual std::ios 
// { 
// public: 
//     MyIOS() 
//     { 
//         init(&_buf); 
//     } 
// protected: 
//     MyStreamBuf _buf; 
// }; 
// 
// class MyIStream: public MyIOS, public std::istream 
// { 
//     ... 
// }; 
// 
// In this scenario, std::ios::init() is called twice 
// (the first time by the MyIOS constructor, the second 
// time by the std::istream constructor), resulting in  
// two locale objects being allocated, the pointer second  
// one overwriting the pointer to the first one and thus  
// causing a memory leak. 
//  
// The workaround is to call init() only once for each 
// stream object - by the istream, ostream or iostream 
// constructor, and not calling init() in ios-derived 
// base classes. 
// 
// Some stream implementations, however, require that 
// init() is called in the MyIOS constructor. 
// Therefore we replace each call to init() with 
// the poco_ios_init macro defined below. 
 
 
#if !defined(POCO_IOS_INIT_HACK) 
	// Microsoft Visual Studio with Dinkumware STL (but not STLport) 
#	if defined(_MSC_VER) && (!defined(_STLP_MSVC) || defined(_STLP_NO_OWN_IOSTREAMS)) 
#		define POCO_IOS_INIT_HACK 1 
    // QNX with Dinkumware but not GNU C++ Library 
#	elif defined(__QNX__) && !defined(__GLIBCPP__) 
#		define POCO_IOS_INIT_HACK 1 
#	endif 
#endif 
 
 
#if defined(POCO_IOS_INIT_HACK) 
#	define poco_ios_init(buf) 
#else 
#	define poco_ios_init(buf) init(buf) 
#endif 
 
 
#endif // Foundation_StreamUtil_INCLUDED