/*=============================================================================

    Copyright (c) 2001-2006 Joel de Guzman



    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)

==============================================================================*/

#if !defined(FUSION_VALUE_AT_IMPL_07172005_0952)

#define FUSION_VALUE_AT_IMPL_07172005_0952



#include <boost/fusion/support/detail/access.hpp>

#include <boost/type_traits/is_const.hpp>

#include <boost/mpl/eval_if.hpp>

#include <boost/mpl/bool.hpp>



namespace boost { namespace fusion

{

    struct cons_tag;



    namespace extension

    {

        template <typename Tag>

        struct value_at_impl;



        template <>

        struct value_at_impl<cons_tag>

        {

            template <typename Sequence, typename N>

            struct apply 

            {

                typedef typename 

                    mpl::eval_if<

                        mpl::bool_<N::value == 0>

                      , mpl::identity<typename Sequence::car_type>

                      , apply<typename Sequence::cdr_type, mpl::int_<N::value-1> >

                    >::type

                type;

            };

        };

    }

}}



#endif

