// (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 0; } 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