/*=============================================================================
    Copyright (c) 2001-2006 Joel de Guzman

    Use, modification and distribution is subject to 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_and_derived.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
{
    struct non_fusion_tag;

    namespace extension
    {
        template<typename T>
        struct is_sequence_impl
            : is_base_and_derived<sequence_root, T>
        {
            template<typename Sequence>
            struct apply 
                : is_base_and_derived<sequence_root, Sequence>
            {};
        };

        template<>
        struct is_sequence_impl<non_fusion_tag>
        {
            template<typename T>
            struct apply : mpl::false_ {};
        };
    }

    namespace traits
    {
        template <typename T>
        struct is_sequence
            : extension::is_sequence_impl<typename detail::tag_of<T>::type>::template apply<T>
        {};
    }
}}

#endif