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(FUSION_END_IMPL_20060123_2208)
9#define FUSION_END_IMPL_20060123_2208
10
11#include <boost/fusion/support/config.hpp>
12#include <boost/fusion/view/zip_view/zip_view_iterator_fwd.hpp>
13#include <boost/fusion/sequence/intrinsic/end.hpp>
14#include <boost/fusion/sequence/intrinsic/begin.hpp>
15#include <boost/fusion/sequence/intrinsic/size.hpp>
16#include <boost/fusion/sequence/intrinsic/front.hpp>
17#include <boost/fusion/iterator/advance.hpp>
18#include <boost/fusion/algorithm/transformation/transform.hpp>
19#include <boost/type_traits/remove_reference.hpp>
20#include <boost/type_traits/is_reference.hpp>
21#include <boost/mpl/assert.hpp>
22#include <boost/mpl/min.hpp>
23
24#include <boost/mpl/eval_if.hpp>
25#include <boost/mpl/identity.hpp>
26#include <boost/type_traits/is_same.hpp>
27
28namespace boost { namespace fusion {
29
30 struct zip_view_tag;
31
32 namespace detail
33 {
34 template<typename SeqRef, typename M>
35 struct get_endpoint
36 {
37 typedef typename remove_reference<SeqRef>::type Seq;
38 typedef typename result_of::begin<Seq>::type begin;
39 typedef typename result_of::advance<begin, M>::type type;
40 };
41
42 template<typename M>
43 struct endpoints
44 {
45 template<typename T>
46 struct result;
47
48 template<typename M1, typename SeqRef>
49 struct result<endpoints<M1>(SeqRef)>
50 : mpl::eval_if<is_same<SeqRef, unused_type const&>,
51 mpl::identity<unused_type>,
52 get_endpoint<SeqRef, M> >
53 {
54 BOOST_MPL_ASSERT((is_reference<SeqRef>));
55 };
56
57 template<typename Seq>
58 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
59 typename result<endpoints(Seq&)>::type
60 operator()(Seq& seq) const
61 {
62 return fusion::advance<M>(fusion::begin(seq));
63 }
64
65 template<typename Seq>
66 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
67 typename result<endpoints(Seq const&)>::type
68 operator()(Seq const& seq) const
69 {
70 return fusion::advance<M>(fusion::begin(seq));
71 }
72
73 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
74 unused_type operator()(unused_type const&) const
75 {
76 return unused_type();
77 }
78 };
79 }
80
81 namespace extension
82 {
83 template<typename Tag>
84 struct end_impl;
85
86 template<>
87 struct end_impl<zip_view_tag>
88 {
89 template<typename Sequence>
90 struct apply
91 {
92 typedef zip_view_iterator<
93 typename result_of::transform<typename Sequence::sequences, detail::endpoints<typename Sequence::size> >::type,
94 typename Sequence::category> type;
95
96 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
97 static type
98 call(Sequence& sequence)
99 {
100 return type(
101 fusion::transform(sequence.sequences_, detail::endpoints<typename Sequence::size>()));
102 }
103 };
104 };
105 }
106}}
107
108#endif
109