ceph/src/boost/libs/fusion/include/boost/fusion/view/transform_view/detail/value_at_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(BOOST_FUSION_VALUE_AT_IMPL_20061101_0745)
   9 #define BOOST_FUSION_VALUE_AT_IMPL_20061101_0745
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/mpl/apply.hpp>
  13 #include <boost/fusion/view/transform_view/detail/apply_transform_result.hpp>
  14 #include <boost/fusion/sequence/intrinsic/value_at.hpp>
  15
  16 namespace boost { namespace fusion {
  17     struct transform_view_tag;
  18     struct transform_view2_tag;
  19
  20     namespace extension
  21     {
  22         template<typename Tag>
  23         struct value_at_impl;
  24
  25         template<>
  26         struct value_at_impl<transform_view_tag>
  27         {
  28             template<typename Seq, typename N>
  29             struct apply
  30             {
  31                 typedef typename Seq::transform_type F;
  32                 typedef detail::apply_transform_result<F> transform_type;
  33                 typedef typename boost::fusion::result_of::value_at<typename Seq::sequence_type, N>::type value_type;
  34                 typedef typename mpl::apply<transform_type, value_type>::type type;
  35             };
  36         };
  37
  38         template<>
  39         struct value_at_impl<transform_view2_tag>
  40         {
  41             template<typename Seq, typename N>
  42             struct apply
  43             {
  44                 typedef typename Seq::transform_type F;
  45                 typedef detail::apply_transform_result<F> transform_type;
  46                 typedef typename boost::fusion::result_of::value_at<typename Seq::sequence1_type, N>::type value1_type;
  47                 typedef typename boost::fusion::result_of::value_at<typename Seq::sequence2_type, N>::type value2_type;
  48                 typedef typename mpl::apply<transform_type, value1_type, value2_type>::type type;
  49             };
  50         };
  51     }
  52 }}
  53
  54 #endif