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// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
// (C) Copyright 2004-2007 Jonathan Turkanis
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
// See http://www.boost.org/libs/iostreams for documentation.
// Inspired by Daryle Walker's nullbuf from his More I/O submission.
#ifndef BOOST_IOSTREAMS_NULL_HPP_INCLUDED
#define BOOST_IOSTREAMS_NULL_HPP_INCLUDED
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/iostreams/categories.hpp>
#include <boost/iostreams/detail/ios.hpp> // openmode, streamsize.
#include <boost/iostreams/positioning.hpp>
namespace boost { namespace iostreams {
template<typename Ch, typename Mode>
class basic_null_device {
public:
typedef Ch char_type;
struct category
: public Mode,
public device_tag,
public closable_tag
{ };
std::streamsize read(Ch*, std::streamsize) { return -1; }
std::streamsize write(const Ch*, std::streamsize n) { return n; }
std::streampos seek( stream_offset, BOOST_IOS::seekdir,
BOOST_IOS::openmode =
BOOST_IOS::in | BOOST_IOS::out )
{ return -1; }
void close() { }
void close(BOOST_IOS::openmode) { }
};
template<typename Ch>
struct basic_null_source : private basic_null_device<Ch, input> {
typedef Ch char_type;
typedef source_tag category;
using basic_null_device<Ch, input>::read;
using basic_null_device<Ch, input>::close;
};
typedef basic_null_source<char> null_source;
typedef basic_null_source<wchar_t> wnull_source;
template<typename Ch>
struct basic_null_sink : private basic_null_device<Ch, output> {
typedef Ch char_type;
typedef sink_tag category;
using basic_null_device<Ch, output>::write;
using basic_null_device<Ch, output>::close;
};
typedef basic_null_sink<char> null_sink;
typedef basic_null_sink<wchar_t> wnull_sink;
} } // End namespaces iostreams, boost.
#endif // #ifndef BOOST_IOSTREAMS_NULL_HPP_INCLUDED
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