ceph/src/boost/libs/fusion/include/boost/fusion/view/reverse_view/detail/distance_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(FUSION_DISTANCE_IMPL_14122005_2104)
   9 #define FUSION_DISTANCE_IMPL_14122005_2104
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/fusion/iterator/distance.hpp>
  13
  14 namespace boost { namespace fusion {
  15
  16     struct reverse_view_iterator_tag;
  17
  18     template <typename Iterator>
  19     struct reverse_view_iterator;
  20
  21     namespace extension
  22     {
  23         template<typename Tag>
  24         struct distance_impl;
  25
  26         template<>
  27         struct distance_impl<reverse_view_iterator_tag>
  28         {
  29             template<typename First, typename Last>
  30             struct apply
  31             {
  32                 typedef typename First::first_type first_type;
  33                 typedef typename Last::first_type last_type;
  34                 typedef typename result_of::distance<last_type, first_type>::type type;
  35
  36                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  37                 static type
  38                 call(First const& first, Last const& last)
  39                 {
  40                     return boost::fusion::distance(last.first, first.first);
  41                 }
  42             };
  43         };
  44     }
  45 }}
  46
  47 #endif