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

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3
   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_AT_IMPL_05042005_0741)
   8 #define FUSION_AT_IMPL_05042005_0741
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/fusion/support/detail/access.hpp>
  12 #include <boost/fusion/container/vector/detail/value_at_impl.hpp>
  13 #include <boost/static_assert.hpp>
  14
  15 namespace boost { namespace fusion
  16 {
  17     struct vector_tag;
  18
  19     namespace extension
  20     {
  21         template <typename Tag>
  22         struct at_impl;
  23
  24         template <>
  25         struct at_impl<vector_tag>
  26         {
  27             template <typename Sequence, typename N>
  28             struct apply
  29             {
  30                 typedef typename value_at_impl<vector_tag>::template apply<Sequence, N>::type element;
  31                 typedef typename detail::ref_result<element>::type type;
  32
  33                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  34                 static type
  35                 call(Sequence& v)
  36                 {
  37                     BOOST_STATIC_ASSERT((N::value < Sequence::size::value));
  38                     return v.at_impl(N());
  39                 }
  40             };
  41
  42             template <typename Sequence, typename N>
  43             struct apply <Sequence const, N>
  44             {
  45                 typedef typename value_at_impl<vector_tag>::template apply<Sequence, N>::type element;
  46                 typedef typename detail::cref_result<element>::type type;
  47
  48                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  49                 static type
  50                 call(Sequence const& v)
  51                 {
  52                     BOOST_STATIC_ASSERT((N::value < Sequence::size::value));
  53                     return v.at_impl(N());
  54                 }
  55             };
  56         };
  57     }
  58 }}
  59
  60 #endif