boost/fusion/iterator/detail/segment_sequence.hpp

   1 /*=============================================================================
   2     Copyright (c) 2011 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_SEGMENTED_SEQUENCE_HPP_INCLUDED)
   8 #define BOOST_FUSION_SEGMENTED_SEQUENCE_HPP_INCLUDED
   9
  10 #include <boost/mpl/bool.hpp>
  11 #include <boost/type_traits/remove_reference.hpp>
  12 #include <boost/fusion/support/tag_of.hpp>
  13 #include <boost/fusion/sequence/intrinsic_fwd.hpp>
  14
  15 namespace boost { namespace fusion { namespace detail
  16 {
  17     struct segment_sequence_tag {};
  18
  19     // Here, Sequence is a sequence of ranges (which may or may not be
  20     // segmented).
  21     template<typename Sequence>
  22     struct segment_sequence
  23         : sequence_base<segment_sequence<Sequence> >
  24     {
  25         typedef fusion_sequence_tag tag;
  26         typedef segment_sequence_tag fusion_tag;
  27         typedef typename Sequence::is_view is_view;
  28         typedef typename Sequence::category category;
  29         typedef Sequence sequence_type;
  30         sequence_type sequence;
  31
  32         explicit segment_sequence(Sequence const & seq)
  33             : sequence(seq)
  34         {}
  35     };
  36 }
  37
  38 namespace extension
  39 {
  40     template<typename Tag>
  41     struct is_segmented_impl;
  42
  43     template<>
  44     struct is_segmented_impl<detail::segment_sequence_tag>
  45     {
  46         template<typename Sequence>
  47         struct apply
  48             : mpl::true_
  49         {};
  50     };
  51
  52     template<typename Tag>
  53     struct segments_impl;
  54
  55     template<>
  56     struct segments_impl<detail::segment_sequence_tag>
  57     {
  58         template<typename Sequence>
  59         struct apply
  60         {
  61             typedef typename Sequence::sequence_type type;
  62
  63             static type call(Sequence & seq)
  64             {
  65                 return seq.sequence;
  66             }
  67         };
  68     };
  69 }}}
  70
  71 #endif