67 lines
2.1 KiB
C++
67 lines
2.1 KiB
C++
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// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
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// (C) Copyright 2004-2007 Jonathan Turkanis
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
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// See http://www.boost.org/libs/iostreams for documentation.
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// Inspired by Daryle Walker's nullbuf from his More I/O submission.
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#ifndef BOOST_IOSTREAMS_NULL_HPP_INCLUDED
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#define BOOST_IOSTREAMS_NULL_HPP_INCLUDED
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#if defined(_MSC_VER)
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# pragma once
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#endif
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#include <boost/iostreams/categories.hpp>
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#include <boost/iostreams/detail/ios.hpp> // openmode, streamsize.
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#include <boost/iostreams/positioning.hpp>
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namespace boost { namespace iostreams {
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template<typename Ch, typename Mode>
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class basic_null_device {
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public:
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typedef Ch char_type;
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struct category
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: public Mode,
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public device_tag,
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public closable_tag
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{ };
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std::streamsize read(Ch*, std::streamsize) { return 0; }
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std::streamsize write(const Ch*, std::streamsize n) { return n; }
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std::streampos seek( stream_offset, BOOST_IOS::seekdir,
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BOOST_IOS::openmode =
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BOOST_IOS::in | BOOST_IOS::out )
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{ return -1; }
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void close() { }
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void close(BOOST_IOS::openmode) { }
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};
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template<typename Ch>
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struct basic_null_source : private basic_null_device<Ch, input> {
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typedef Ch char_type;
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typedef source_tag category;
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using basic_null_device<Ch, input>::read;
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using basic_null_device<Ch, input>::close;
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};
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typedef basic_null_source<char> null_source;
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typedef basic_null_source<wchar_t> wnull_source;
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template<typename Ch>
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struct basic_null_sink : private basic_null_device<Ch, output> {
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typedef Ch char_type;
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typedef sink_tag category;
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using basic_null_device<Ch, output>::write;
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using basic_null_device<Ch, output>::close;
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};
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typedef basic_null_sink<char> null_sink;
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typedef basic_null_sink<wchar_t> wnull_sink;
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} } // End namespaces iostreams, boost.
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#endif // #ifndef BOOST_IOSTREAMS_NULL_HPP_INCLUDED
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