ceph/src/boost/boost/fusion/iterator/advance.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_ADVANCE_09172005_1146)
   8 #define FUSION_ADVANCE_09172005_1146
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/fusion/iterator/detail/advance.hpp>
  12 #include <boost/fusion/support/category_of.hpp>
  13
  14 #include <boost/mpl/int.hpp>
  15 #include <boost/mpl/assert.hpp>
  16 #include <boost/type_traits/is_same.hpp>
  17 #include <boost/fusion/support/tag_of.hpp>
  18
  19 namespace boost { namespace fusion
  20 {
  21     struct random_access_traversal_tag;
  22
  23     // Special tags:
  24     struct iterator_facade_tag; // iterator facade tag
  25     struct boost_array_iterator_tag; // boost::array iterator tag
  26     struct mpl_iterator_tag; // mpl sequence iterator tag
  27     struct std_pair_iterator_tag; // std::pair iterator tag
  28
  29     namespace extension
  30     {
  31         template <typename Tag>
  32         struct advance_impl
  33         {
  34             // default implementation
  35             template <typename Iterator, typename N>
  36             struct apply :
  37                 mpl::if_c<
  38                     (N::value > 0)
  39                   , advance_detail::forward<Iterator, N::value>
  40                   , advance_detail::backward<Iterator, N::value>
  41                 >::type
  42             {
  43                 BOOST_MPL_ASSERT_NOT((traits::is_random_access<Iterator>));
  44             };
  45         };
  46
  47         template <>
  48         struct advance_impl<iterator_facade_tag>
  49         {
  50             template <typename Iterator, typename N>
  51             struct apply : Iterator::template advance<Iterator, N> {};
  52         };
  53
  54         template <>
  55         struct advance_impl<boost_array_iterator_tag>;
  56
  57         template <>
  58         struct advance_impl<mpl_iterator_tag>;
  59
  60         template <>
  61         struct advance_impl<std_pair_iterator_tag>;
  62     }
  63
  64     namespace result_of
  65     {
  66         template <typename Iterator, int N>
  67         struct advance_c
  68             : extension::advance_impl<typename detail::tag_of<Iterator>::type>::template apply<Iterator, mpl::int_<N> >
  69         {};
  70
  71         template <typename Iterator, typename N>
  72         struct advance
  73             : extension::advance_impl<typename detail::tag_of<Iterator>::type>::template apply<Iterator, N>
  74         {};
  75     }
  76
  77     template <int N, typename Iterator>
  78     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  79     inline typename result_of::advance_c<Iterator, N>::type const
  80     advance_c(Iterator const& i)
  81     {
  82         return result_of::advance_c<Iterator, N>::call(i);
  83     }
  84
  85     template<typename N, typename Iterator>
  86     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  87     inline typename result_of::advance<Iterator, N>::type const
  88     advance(Iterator const& i)
  89     {
  90         return result_of::advance<Iterator, N>::call(i);
  91     }
  92
  93 }} // namespace boost::fusion
  94
  95 #endif