3rdparty/boost/boost/fusion/sequence/intrinsic/segments.hpp

   1 /*=============================================================================
   2     Copyright (c) 2006 Eric Niebler
   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_SEGMENTS_04052005_1141)
   8 #define BOOST_FUSION_SEGMENTS_04052005_1141
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/type_traits/is_const.hpp>
  12 #include <boost/utility/enable_if.hpp>
  13 #include <boost/fusion/sequence/intrinsic_fwd.hpp>
  14 #include <boost/fusion/support/tag_of.hpp>
  15
  16 namespace boost { namespace fusion
  17 {
  18     // Special tags:
  19     struct sequence_facade_tag;
  20     struct iterator_range_tag;
  21
  22     // segments: returns a sequence of sequences
  23     namespace extension
  24     {
  25         template <typename Tag>
  26         struct segments_impl
  27         {
  28             template <typename Sequence>
  29             struct apply {};
  30         };
  31
  32         template <>
  33         struct segments_impl<sequence_facade_tag>
  34         {
  35             template <typename Sequence>
  36             struct apply : Sequence::template segments<Sequence> {};
  37         };
  38
  39         template <>
  40         struct segments_impl<iterator_range_tag>;
  41     }
  42
  43     namespace result_of
  44     {
  45         template <typename Sequence>
  46         struct segments
  47         {
  48             typedef typename traits::tag_of<Sequence>::type tag_type;
  49
  50             typedef typename
  51                 extension::segments_impl<tag_type>::template apply<Sequence>::type
  52             type;
  53         };
  54     }
  55
  56     template <typename Sequence>
  57     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  58     inline typename
  59         lazy_disable_if<
  60             is_const<Sequence>
  61           , result_of::segments<Sequence>
  62         >::type
  63     segments(Sequence& seq)
  64     {
  65         typedef typename traits::tag_of<Sequence>::type tag_type;
  66         return extension::segments_impl<tag_type>::template apply<Sequence>::call(seq);
  67     }
  68
  69     template <typename Sequence>
  70     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  71     inline typename result_of::segments<Sequence const>::type
  72     segments(Sequence const& seq)
  73     {
  74         typedef typename traits::tag_of<Sequence const>::type tag_type;
  75         return extension::segments_impl<tag_type>::template apply<Sequence const>::call(seq);
  76     }
  77 }}
  78
  79 #endif