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//
// NullStream.h
//
// Library: Foundation
// Package: Streams
// Module: NullStream
//
// Definition of the NullStreamBuf, NullInputStream and NullOutputStream classes.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_NullStream_INCLUDED
#define Foundation_NullStream_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/UnbufferedStreamBuf.h"
#include <istream>
#include <ostream>
namespace Poco {
class Foundation_API NullStreamBuf: public UnbufferedStreamBuf
/// This stream buffer discards all characters written to it.
/// Any read operation immediately yields EOF.
{
public:
NullStreamBuf();
/// Creates a NullStreamBuf.
~NullStreamBuf();
/// Destroys the NullStreamBuf.
protected:
int readFromDevice();
int writeToDevice(char c);
};
class Foundation_API NullIOS: public virtual std::ios
/// The base class for NullInputStream and NullOutputStream.
///
/// This class is needed to ensure the correct initialization
/// order of the stream buffer and base classes.
{
public:
NullIOS();
~NullIOS();
protected:
NullStreamBuf _buf;
};
class Foundation_API NullInputStream: public NullIOS, public std::istream
/// Any read operation from this stream immediately
/// yields EOF.
{
public:
NullInputStream();
/// Creates the NullInputStream.
~NullInputStream();
/// Destroys the NullInputStream.
};
class Foundation_API NullOutputStream: public NullIOS, public std::ostream
/// This stream discards all characters written to it.
{
public:
NullOutputStream();
/// Creates the NullOutputStream.
~NullOutputStream();
/// Destroys the NullOutputStream.
};
} // namespace Poco
#endif // Foundation_NullStream_INCLUDED
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