ceph/src/boost/libs/fusion/include/boost/fusion/container/vector/detail/distance_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_DISTANCE_IMPL_09172005_0751)
   8 #define FUSION_DISTANCE_IMPL_09172005_0751
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/mpl/minus.hpp>
  12
  13 namespace boost { namespace fusion
  14 {
  15     struct vector_iterator_tag;
  16
  17     namespace extension
  18     {
  19         template <typename Tag>
  20         struct distance_impl;
  21
  22         template <>
  23         struct distance_impl<vector_iterator_tag>
  24         {
  25             template <typename First, typename Last>
  26             struct apply : mpl::minus<typename Last::index, typename First::index>
  27             {
  28                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  29                 static typename mpl::minus<
  30                     typename Last::index, typename First::index>::type
  31                 call(First const&, Last const&)
  32                 {
  33                     typedef typename mpl::minus<
  34                         typename Last::index, typename First::index>::type
  35                     result;
  36                     return result();
  37                 }
  38             };
  39         };
  40     }
  41 }}
  42
  43 #endif