deps/boost_1_63_0/boost/fusion/adapted/boost_tuple/detail/end_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(BOOST_FUSION_END_IMPL_09272006_0721)
   8 #define BOOST_FUSION_END_IMPL_09272006_0721
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/fusion/adapted/boost_tuple/boost_tuple_iterator.hpp>
  12 #include <boost/mpl/if.hpp>
  13 #include <boost/type_traits/is_const.hpp>
  14
  15 namespace boost { namespace tuples
  16 {
  17     struct null_type;
  18 }}
  19
  20 namespace boost { namespace fusion
  21 {
  22     struct boost_tuple_tag;
  23
  24     namespace extension
  25     {
  26         template <typename Tag>
  27         struct end_impl;
  28
  29         template <>
  30         struct end_impl<boost_tuple_tag>
  31         {
  32             template <typename Sequence>
  33             struct apply
  34             {
  35                 typedef
  36                     boost_tuple_iterator<
  37                         typename mpl::if_<
  38                             is_const<Sequence>
  39                           , tuples::null_type const
  40                           , tuples::null_type
  41                         >::type
  42                     >
  43                 type;
  44
  45                 BOOST_FUSION_GPU_ENABLED
  46                 static type
  47                 call(Sequence& seq)
  48                 {
  49                     return type(seq);
  50                 }
  51             };
  52         };
  53     }
  54 }}
  55
  56 #endif