ceph/src/boost/libs/fusion/example/extension/detail/distance_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3     Copyright (c) 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(BOOST_FUSION_DISTANCE_IMPL_20060223_0814)
   9 #define BOOST_FUSION_DISTANCE_IMPL_20060223_0814
  10
  11 #include <boost/mpl/minus.hpp>
  12
  13 namespace example
  14 {
  15     struct example_struct_iterator_tag;
  16 }
  17
  18 namespace boost { namespace fusion {
  19
  20     namespace extension
  21     {
  22         template<typename Tag>
  23         struct distance_impl;
  24
  25         template<>
  26         struct distance_impl<example::example_struct_iterator_tag>
  27         {
  28             template<typename First, typename Last>
  29             struct apply
  30                 : mpl::minus<typename Last::index, typename First::index>
  31             {
  32                 typedef apply<First, Last> self;
  33
  34                 static typename self::type
  35                 call(First const& first, Last const& last)
  36                 {
  37                     return typename self::type();
  38                 }
  39             };
  40         };
  41     }
  42 }}
  43
  44 #endif