// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)

// (C) Copyright 2003-2007 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.



// Contains machinery for performing code conversion.



#ifndef BOOST_IOSTREAMS_DETAIL_CODECVT_HOLDER_HPP_INCLUDED

#define BOOST_IOSTREAMS_DETAIL_CODECVT_HOLDER_HPP_INCLUDED



#if defined(_MSC_VER) && (_MSC_VER >= 1020)

# pragma once

#endif



#include <cwchar>            // mbstate_t.

#include <locale>            // codecvt, locale.

#include <boost/config.hpp>  // HAS_MACRO_USE_FACET.

#include <boost/iostreams/detail/config/codecvt.hpp>



namespace boost { namespace iostreams { namespace detail {



struct default_codecvt { 

    typedef wchar_t         intern_type, from_type;

    typedef char            extern_type, to_type;

    typedef std::mbstate_t  state_type;

};



template<typename Codecvt>

struct codecvt_holder {

    typedef Codecvt codecvt_type;

    const codecvt_type& get() const { return codecvt_; }

    void imbue(const std::locale&) { }

    Codecvt codecvt_;

};



template<>

struct codecvt_holder<default_codecvt> {

    typedef std::codecvt<wchar_t, char, std::mbstate_t> codecvt_type;

    codecvt_holder() { reset_codecvt(); }

    const codecvt_type& get() const { return *codecvt_; }

    void imbue(const std::locale& loc) 

    { 

        loc_ = loc;

        reset_codecvt();

    }

    void reset_codecvt()

    {

        using namespace std;

        #ifndef BOOST_HAS_MACRO_USE_FACET

            codecvt_ = & use_facet< codecvt_type >(loc_);

        #else

            codecvt_ = & _USE(loc_, codecvt_type);

        #endif

    }

    std::locale loc_; // Prevent codecvt_ from being freed.

    const codecvt_type* codecvt_;

};



} } } // End namespaces detail, iostreams, boost.



#endif // #ifndef BOOST_IOSTREAMS_DETAIL_CODECVT_HOLDER_HPP_INCLUDED

