text: /*=============================================================================
      Copyright (c) 2001-2011 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/fusion/support/config.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>
  #include <boost/type_traits/is_convertible.hpp>
  #include <boost/type_traits/is_same.hpp>
  
  namespace boost { namespace fusion
  {
      // Special tags:
      struct non_fusion_tag;
      struct boost_tuple_tag; // boost::tuples::tuple tag
      struct boost_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_convertible<Sequence, fusion::detail::from_sequence_convertible_type>
              {};
          };
  
          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<boost_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
            : mpl::bool_<
                  (bool)extension::is_sequence_impl<
                      typename fusion::detail::tag_of<T>::type
                  >::template apply<T>::type::value
              >
          {};
  
          template <typename Sequence, typename Enable = void>
          struct is_native_fusion_sequence
            : is_convertible<Sequence, fusion::detail::from_sequence_convertible_type>
          {};
      }
  }}
  
  #endif
  