3rdparty/boost/boost/fusion/container/vector/detail/deref_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_DEREF_IMPL_05042005_1037)
   8 #define FUSION_DEREF_IMPL_05042005_1037
   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/type_traits/is_const.hpp>
  14 #include <boost/mpl/if.hpp>
  15
  16 namespace boost { namespace fusion
  17 {
  18     struct vector_iterator_tag;
  19
  20     namespace extension
  21     {
  22         template <typename Tag>
  23         struct deref_impl;
  24
  25         template <>
  26         struct deref_impl<vector_iterator_tag>
  27         {
  28             template <typename Iterator>
  29             struct apply
  30             {
  31                 typedef typename Iterator::vector vector;
  32                 typedef typename Iterator::index index;
  33                 typedef typename value_at_impl<vector_tag>::template apply<vector, index>::type element;
  34
  35                 typedef typename
  36                     mpl::if_<
  37                         is_const<vector>
  38                       , typename fusion::detail::cref_result<element>::type
  39                       , typename fusion::detail::ref_result<element>::type
  40                     >::type
  41                 type;
  42
  43                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  44                 static type
  45                 call(Iterator const& i)
  46                 {
  47                     return i.vec.at_impl(index());
  48                 }
  49             };
  50         };
  51     }
  52 }}
  53
  54 #endif