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
segments(Sequence & seq)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
segments(Sequence const & seq)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
80