/*============================================================================= 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_VALUE_AT_05052005_0229) #define FUSION_VALUE_AT_05052005_0229 #include <boost/fusion/support/config.hpp> #include <boost/mpl/int.hpp> #include <boost/fusion/sequence/intrinsic_fwd.hpp> #include <boost/fusion/support/tag_of.hpp> namespace boost { namespace fusion { // Special tags: struct sequence_facade_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 Tag> struct value_at_impl { template <typename Sequence, typename N> struct apply; }; template <> struct value_at_impl<sequence_facade_tag> { template <typename Sequence, typename N> struct apply : Sequence::template value_at<Sequence, N> {}; }; template <> struct value_at_impl<boost_tuple_tag>; template <> struct value_at_impl<boost_array_tag>; template <> struct value_at_impl<mpl_sequence_tag>; template <> struct value_at_impl<std_pair_tag>; } namespace result_of { template <typename Sequence, typename N> struct value_at : extension::value_at_impl<typename detail::tag_of<Sequence>::type>:: template apply<Sequence, N> {}; template <typename Sequence, int N> struct value_at_c : fusion::result_of::value_at<Sequence, mpl::int_<N> > {}; } }} #endif