ceph/src/boost/boost/fusion/sequence/intrinsic/back.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_BACK_09162005_0350)
   8 #define FUSION_BACK_09162005_0350
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/fusion/sequence/intrinsic_fwd.hpp>
  12 #include <boost/fusion/sequence/intrinsic/end.hpp>
  13 #include <boost/fusion/iterator/prior.hpp>
  14 #include <boost/fusion/iterator/deref.hpp>
  15 #include <boost/mpl/bool.hpp>
  16
  17 namespace boost { namespace fusion
  18 {
  19     struct fusion_sequence_tag;
  20
  21     namespace result_of
  22     {
  23         template <typename Sequence>
  24         struct back
  25             : result_of::deref<typename result_of::prior<typename result_of::end<Sequence>::type>::type>
  26         {};
  27     }
  28
  29     template <typename Sequence>
  30     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  31     inline typename result_of::back<Sequence>::type
  32     back(Sequence& seq)
  33     {
  34         return *fusion::prior(fusion::end(seq));
  35     }
  36
  37     template <typename Sequence>
  38     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  39     inline typename result_of::back<Sequence const>::type
  40     back(Sequence const& seq)
  41     {
  42         return *fusion::prior(fusion::end(seq));
  43     }
  44 }}
  45
  46 #endif