1 /*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
4 Distributed under the Boost Software License, Version 1.0. (See accompanying
5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 ==============================================================================*/
7 #if !defined(FUSION_VALUE_AT_05052005_0229)
8 #define FUSION_VALUE_AT_05052005_0229
10 #include <boost/mpl/int.hpp>
11 #include <boost/fusion/sequence/intrinsic_fwd.hpp>
12 #include <boost/fusion/support/tag_of.hpp>
14 namespace boost { namespace fusion
17 struct sequence_facade_tag;
18 struct boost_tuple_tag; // boost::tuples::tuple tag
19 struct boost_array_tag; // boost::array tag
20 struct mpl_sequence_tag; // mpl sequence tag
21 struct std_pair_tag; // std::pair tag
25 template <typename Tag>
28 template <typename Sequence, typename N>
33 struct value_at_impl<sequence_facade_tag>
35 template <typename Sequence, typename N>
36 struct apply : Sequence::template value_at<Sequence, N> {};
40 struct value_at_impl<boost_tuple_tag>;
43 struct value_at_impl<boost_array_tag>;
46 struct value_at_impl<mpl_sequence_tag>;
49 struct value_at_impl<std_pair_tag>;
54 template <typename Sequence, typename N>
56 : extension::value_at_impl<typename detail::tag_of<Sequence>::type>::
57 template apply<Sequence, N>
60 template <typename Sequence, int N>
62 : fusion::result_of::value_at<Sequence, mpl::int_<N> >