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

    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_IS_SEQUENCE_05052005_1002)

#define FUSION_IS_SEQUENCE_05052005_1002



#include <boost/type_traits/is_base_of.hpp>

#include <boost/fusion/support/sequence_base.hpp>

#include <boost/fusion/support/tag_of.hpp>

#include <boost/mpl/is_sequence.hpp>

#include <boost/mpl/or.hpp>

#include <boost/mpl/bool.hpp>



namespace boost { namespace fusion

{

    // Special tags:

    struct non_fusion_tag;

    struct boost_tuple_tag; // boost::tuples::tuple tag

    struct array_tag; // boost::array tag

    struct mpl_sequence_tag; // mpl sequence tag

    struct std_pair_tag; // std::pair tag



    namespace extension

    {

        template <typename T>

        struct is_sequence_impl

        {

            template <typename Sequence>

            struct apply : is_base_of<sequence_root, Sequence> {};

        };



        template <>

        struct is_sequence_impl<non_fusion_tag>

        {

            template <typename T>

            struct apply : mpl::false_ {};

        };



        template <>

        struct is_sequence_impl<boost_tuple_tag>;



        template <>

        struct is_sequence_impl<array_tag>;



        template <>

        struct is_sequence_impl<mpl_sequence_tag>;



        template <>

        struct is_sequence_impl<std_pair_tag>;

    }



    namespace traits

    {

        template <typename T>

        struct is_sequence

            : extension::is_sequence_impl<typename detail::tag_of<T>::type>::

                template apply<T>

        {};

    }

}}



#endif

