// (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.



#ifndef BOOST_IOSTREAMS_OPTIMAL_BUFFER_SIZE_HPP_INCLUDED

#define BOOST_IOSTREAMS_OPTIMAL_BUFFER_SIZE_HPP_INCLUDED



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

# pragma once

#endif



#include <boost/config.hpp>  // DEDUCED_TYPENAME, MSVC.

#include <boost/detail/workaround.hpp>

#include <boost/iostreams/constants.hpp>  // constants.

#include <boost/iostreams/detail/dispatch.hpp>

#include <boost/iostreams/detail/wrap_unwrap.hpp>

#include <boost/iostreams/operations_fwd.hpp>

#include <boost/mpl/if.hpp>



// Must come last.

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



namespace boost { namespace iostreams {



namespace detail {



template<typename T>

struct optimal_buffer_size_impl;



} // End namespace detail.



template<typename T>

std::streamsize optimal_buffer_size(const T& t)

{

    typedef detail::optimal_buffer_size_impl<T> impl;

    return impl::optimal_buffer_size(detail::unwrap(t));

}



namespace detail {



//------------------Definition of optimal_buffer_size_impl--------------------//



template<typename T>

struct optimal_buffer_size_impl

    : mpl::if_<

          is_custom<T>,

          operations<T>,

          optimal_buffer_size_impl<

              BOOST_DEDUCED_TYPENAME

              dispatch<

                  T, optimally_buffered_tag, device_tag, filter_tag

              >::type

          >

      >::type

    { };



template<>

struct optimal_buffer_size_impl<optimally_buffered_tag> {

    template<typename T>

    static std::streamsize optimal_buffer_size(const T& t)

    { return t.optimal_buffer_size(); }

};



template<>

struct optimal_buffer_size_impl<device_tag> {

    template<typename T>

    static std::streamsize optimal_buffer_size(const T&)

    { return default_device_buffer_size; }

};



template<>

struct optimal_buffer_size_impl<filter_tag> {

    template<typename T>

    static std::streamsize optimal_buffer_size(const T&)

    { return default_filter_buffer_size; }

};



} // End namespace detail.



} } // End namespaces iostreams, boost.



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



#endif // #ifndef BOOST_IOSTREAMS_OPTIMAL_BUFFER_SIZE_HPP_INCLUDED

