#ifndef BOOST_MPL_O1_SIZE_IMPL_HPP_INCLUDED

#define BOOST_MPL_O1_SIZE_IMPL_HPP_INCLUDED

// Copyright Aleksey Gurtovoy 2000-2004

//

// 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/mpl for documentation.

// $Source: /cvsroot/boost/boost/boost/mpl/aux_/O1_size_impl.hpp,v $

// $Date: 2004/09/02 15:40:42 $

// $Revision: 1.4 $

#include <boost/mpl/O1_size_fwd.hpp>

#include <boost/mpl/long.hpp>

#include <boost/mpl/if.hpp>

#include <boost/mpl/aux_/has_size.hpp>

#include <boost/mpl/aux_/config/forwarding.hpp>

#include <boost/mpl/aux_/config/static_constant.hpp>

#include <boost/mpl/aux_/config/msvc.hpp>

#include <boost/mpl/aux_/config/workaround.hpp>

namespace boost { namespace mpl {

// default implementation - returns 'Sequence::size' if sequence has a 'size'

// member, and -1 otherwise; conrete sequences might override it by 

// specializing either the 'O1_size_impl' or the primary 'O1_size' template

#   if !BOOST_WORKAROUND(BOOST_MSVC, < 1300) \

    && !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))

namespace aux {

template< typename Sequence > struct O1_size_impl

    : Sequence::size

{

};

}

template< typename Tag >

struct O1_size_impl

{

    template< typename Sequence > struct apply

#if !defined(BOOST_MPL_CFG_NO_NESTED_FORWARDING)

        : if_<

              aux::has_size<Sequence>

            , aux::O1_size_impl<Sequence>

            , long_<-1>

            >::type

    {

#else

    {

        typedef typename if_<

              aux::has_size<Sequence>

            , aux::O1_size_impl<Sequence>

            , long_<-1>

            >::type type;

        BOOST_STATIC_CONSTANT(long, value =

              (if_<

                  aux::has_size<Sequence>

                , aux::O1_size_impl<Sequence>

                , long_<-1>

                >::type::value)

            );

#endif

    };

};

#   else // BOOST_MSVC

template< typename Tag >

struct O1_size_impl

{

    template< typename Sequence > struct apply

        : long_<-1>

        {

        };

};

#   endif

}}

#endif // BOOST_MPL_O1_SIZE_IMPL_HPP_INCLUDED