ceph/src/boost/libs/fusion/include/boost/fusion/view/nview/detail/at_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2009 Hartmut Kaiser
   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
   8 #if !defined(BOOST_FUSION_NVIEW_AT_IMPL_SEP_24_2009_0225PM)
   9 #define BOOST_FUSION_NVIEW_AT_IMPL_SEP_24_2009_0225PM
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/fusion/sequence/intrinsic/at.hpp>
  13 #include <boost/fusion/sequence/intrinsic/value_at.hpp>
  14
  15 namespace boost { namespace fusion
  16 {
  17     struct nview_tag;
  18
  19     namespace extension
  20     {
  21         template<typename Tag>
  22         struct at_impl;
  23
  24         template<>
  25         struct at_impl<nview_tag>
  26         {
  27             template<typename Sequence, typename N>
  28             struct apply
  29             {
  30                 typedef typename Sequence::sequence_type sequence_type;
  31                 typedef typename Sequence::index_type index_type;
  32
  33                 typedef typename result_of::value_at<index_type, N>::type index;
  34                 typedef typename result_of::at<sequence_type, index>::type type;
  35
  36                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  37                 static type
  38                 call(Sequence& seq)
  39                 {
  40                     return fusion::at<index>(seq.seq);
  41                 }
  42             };
  43         };
  44     }
  45
  46 }}
  47
  48 #endif