ceph/src/boost/libs/fusion/include/boost/fusion/container/map/detail/cpp03/at_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3     Copyright (c) 2011 Brandon Kohn
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 ==============================================================================*/
   8 #if !defined(BOOST_FUSION_MAP_DETAIL_AT_IMPL_HPP)
   9 #define BOOST_FUSION_MAP_DETAIL_AT_IMPL_HPP
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/fusion/support/detail/access.hpp>
  13 #include <boost/type_traits/is_const.hpp>
  14 #include <boost/mpl/at.hpp>
  15 #include <boost/mpl/int.hpp>
  16
  17 namespace boost { namespace fusion
  18 {
  19     struct map_tag;
  20
  21     namespace extension
  22     {
  23         template <typename Tag>
  24         struct at_impl;
  25
  26         template <>
  27         struct at_impl<map_tag>
  28         {
  29             template <typename Sequence, typename N>
  30             struct apply
  31             {
  32                 typedef typename
  33                     mpl::at<typename Sequence::storage_type::types, N>::type
  34                 element;
  35                 typedef typename detail::ref_result<element>::type type;
  36
  37                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  38                 static type
  39                 call(Sequence& m)
  40                 {
  41                     return m.get_data().at_impl(N());
  42                 }
  43             };
  44
  45             template <typename Sequence, typename N>
  46             struct apply<Sequence const, N>
  47             {
  48                 typedef typename
  49                     mpl::at<typename Sequence::storage_type::types, N>::type
  50                 element;
  51                 typedef typename detail::cref_result<element>::type type;
  52
  53                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  54                 static type
  55                 call(Sequence const& m)
  56                 {
  57                     return m.get_data().at_impl(N());
  58                 }
  59             };
  60         };
  61     }
  62 }}
  63
  64 #endif //BOOST_FUSION_MAP_DETAIL_AT_IMPL_HPP