ceph/src/boost/libs/fusion/include/boost/fusion/view/reverse_view/detail/advance_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_ADVANCE_IMPL_14122005_2015)
   9 #define FUSION_ADVANCE_IMPL_14122005_2015
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/fusion/iterator/advance.hpp>
  13 #include <boost/mpl/negate.hpp>
  14
  15 namespace boost { namespace fusion {
  16
  17     struct reverse_view_iterator_tag;
  18
  19     template <typename Iterator>
  20     struct reverse_view_iterator;
  21
  22     namespace extension
  23     {
  24         template<typename Tag>
  25         struct advance_impl;
  26
  27         template<>
  28         struct advance_impl<reverse_view_iterator_tag>
  29         {
  30             template<typename Iterator, typename Dist>
  31             struct apply
  32             {
  33                 typedef typename Iterator::first_type first_type;
  34                 typedef typename mpl::negate<Dist>::type negative_dist;
  35                 typedef typename result_of::advance<first_type, negative_dist>::type advanced_type;
  36                 typedef reverse_view_iterator<advanced_type> type;
  37
  38                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  39                 static type
  40                 call(Iterator const& i)
  41                 {
  42                     return type(boost::fusion::advance<negative_dist>(i.first));
  43                 }
  44             };
  45         };
  46     }
  47 }}
  48
  49 #endif