deps/boost_1_63_0/boost/fusion/adapted/boost_array/detail/at_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3     Copyright (c) 2005-2006 Dan Marsden
   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_AT_IMPL_27122005_1241)
   9 #define BOOST_FUSION_AT_IMPL_27122005_1241
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/type_traits/is_const.hpp>
  13
  14 #include <boost/mpl/if.hpp>
  15
  16 namespace boost { namespace fusion {
  17
  18     struct boost_array_tag;
  19
  20     namespace extension
  21     {
  22         template<typename T>
  23         struct at_impl;
  24
  25         template<>
  26         struct at_impl<boost_array_tag>
  27         {
  28             template<typename Sequence, typename N>
  29             struct apply
  30             {
  31                 typedef typename mpl::if_<
  32                     is_const<Sequence>,
  33                     typename Sequence::const_reference,
  34                     typename Sequence::reference>::type type;
  35
  36                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  37                 static type
  38                 call(Sequence& seq)
  39                 {
  40                     return seq[N::value];
  41                 }
  42             };
  43         };
  44     }
  45 }}
  46
  47 #endif