ceph/src/boost/libs/fusion/include/boost/fusion/sequence/intrinsic/swap.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_SWAP_20070501_1956)
   9 #define BOOST_FUSION_SWAP_20070501_1956
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <algorithm>
  13
  14 #include <boost/fusion/support/is_sequence.hpp>
  15 #include <boost/fusion/view/zip_view.hpp>
  16 #include <boost/fusion/algorithm/iteration/for_each.hpp>
  17 #include <boost/fusion/sequence/intrinsic/front.hpp>
  18 #include <boost/fusion/sequence/intrinsic/back.hpp>
  19 #include <boost/core/enable_if.hpp>
  20 #include <boost/mpl/and.hpp>
  21
  22 namespace boost { namespace fusion {
  23
  24     namespace result_of
  25     {
  26         template<typename Seq1, typename Seq2>
  27         struct swap
  28             : enable_if<mpl::and_<
  29                   traits::is_sequence<Seq1>,
  30                   traits::is_sequence<Seq2>
  31               > > {};
  32     }
  33
  34     namespace detail
  35     {
  36         struct swap
  37         {
  38             template<typename Elem>
  39             struct result
  40             {
  41                 typedef void type;
  42             };
  43
  44             template<typename Elem>
  45             BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  46             void operator()(Elem const& e) const
  47             {
  48                 using std::swap;
  49                 swap(front(e), back(e));
  50             }
  51         };
  52     }
  53
  54     template<typename Seq1, typename Seq2>
  55     BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  56     inline typename result_of::swap<Seq1, Seq2>::type
  57     swap(Seq1& lhs, Seq2& rhs)
  58     {
  59         typedef vector<Seq1&, Seq2&> references;
  60         for_each(zip_view<references>(references(lhs, rhs)), detail::swap());
  61     }
  62 }}
  63
  64 #endif