3rdparty/boost/boost/fusion/view/iterator_range/detail/at_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2007 Tobias Schwinger
   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_ITERATOR_RANGE_AT_IMPL_HPP_INCLUDED)
   9 #define BOOST_FUSION_ITERATOR_RANGE_AT_IMPL_HPP_INCLUDED
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/fusion/iterator/advance.hpp>
  13 #include <boost/fusion/iterator/deref.hpp>
  14
  15 namespace boost { namespace fusion
  16 {
  17     struct iterator_range_tag;
  18
  19     namespace extension
  20     {
  21         template <typename Tag>
  22         struct at_impl;
  23
  24         template <>
  25         struct at_impl<iterator_range_tag>
  26         {
  27             template <typename Seq, typename N>
  28             struct apply
  29             {
  30                 typedef typename Seq::begin_type begin_type;
  31                 typedef typename result_of::advance<begin_type,N>::type pos;
  32                 typedef typename result_of::deref<pos>::type type;
  33
  34                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  35                 static type
  36                 call(Seq& s)
  37                 {
  38                     return * fusion::advance<N>(s.first);
  39                 }
  40             };
  41         };
  42     }
  43 }}
  44
  45 #endif
  46