// (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) && (_MSC_VER >= 1020)

# 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

