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_ZIP_VIEW_23012006_0813)
9#define FUSION_ZIP_VIEW_23012006_0813
10
11#include <boost/fusion/support/config.hpp>
12#include <boost/fusion/support/sequence_base.hpp>
13#include <boost/fusion/support/unused.hpp>
14#include <boost/fusion/iterator/equal_to.hpp>
15#include <boost/fusion/view/detail/strictest_traversal.hpp>
16#include <boost/fusion/view/zip_view/detail/begin_impl.hpp>
17#include <boost/fusion/view/zip_view/detail/end_impl.hpp>
18#include <boost/fusion/view/zip_view/detail/size_impl.hpp>
19#include <boost/fusion/view/zip_view/detail/at_impl.hpp>
20#include <boost/fusion/view/zip_view/detail/value_at_impl.hpp>
21#include <boost/fusion/container/vector/convert.hpp>
22#include <boost/fusion/algorithm/query/find_if.hpp>
23#include <boost/fusion/sequence/intrinsic/end.hpp>
24#include <boost/fusion/sequence/intrinsic/size.hpp>
25#include <boost/fusion/mpl.hpp>
26#include <boost/fusion/algorithm/transformation/remove.hpp>
27
28#include <boost/mpl/assert.hpp>
29#include <boost/mpl/not.hpp>
30#include <boost/mpl/placeholders.hpp>
31#include <boost/mpl/transform_view.hpp>
32#include <boost/mpl/at.hpp>
33#include <boost/mpl/find_if.hpp>
34#include <boost/mpl/equal_to.hpp>
35#include <boost/mpl/bool.hpp>
36#include <boost/mpl/eval_if.hpp>
37
38#include <boost/type_traits/remove_reference.hpp>
39#include <boost/type_traits/is_reference.hpp>
40
41#include <boost/config.hpp>
42
43namespace boost { namespace fusion {
44
45 namespace detail
46 {
47 template<typename Sequences>
48 struct all_references
49 : fusion::result_of::equal_to<typename fusion::result_of::find_if<Sequences, mpl::not_<is_reference<mpl::_> > >::type, typename fusion::result_of::end<Sequences>::type>
50 {};
51
52 struct seq_ref_size
53 {
54 template<typename Params>
55 struct result;
56
57 template<typename Seq>
58 struct result<seq_ref_size(Seq)>
59 {
60 static int const high_int = static_cast<int>(
61 (static_cast<unsigned>(~0) >> 1) - 1);
62
63 typedef typename remove_reference<Seq>::type SeqClass;
64
65 typedef typename mpl::eval_if<
66 traits::is_forward<SeqClass>,
67 result_of::size<SeqClass>,
68 mpl::int_<high_int> >::type type;
69 };
70
71 // never called, but needed for decltype-based result_of (C++0x)
72#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
73 template<typename Seq>
74 BOOST_FUSION_GPU_ENABLED
75 typename result<seq_ref_size(Seq)>::type
76 operator()(Seq&&) const;
77#endif
78 };
79
80 struct poly_min
81 {
82 template<typename T>
83 struct result;
84
85 template<typename Lhs, typename Rhs>
86 struct result<poly_min(Lhs, Rhs)>
87 {
88 typedef typename remove_reference<Lhs>::type lhs;
89 typedef typename remove_reference<Rhs>::type rhs;
90 typedef typename mpl::min<lhs, rhs>::type type;
91 };
92
93 // never called, but needed for decltype-based result_of (C++0x)
94#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
95 template<typename Lhs, typename Rhs>
96 BOOST_FUSION_GPU_ENABLED
97 typename result<poly_min(Lhs, Rhs)>::type
98 operator()(Lhs&&, Rhs&&) const;
99#endif
100 };
101
102 template<typename Sequences>
103 struct min_size
104 {
105 typedef typename result_of::transform<Sequences, detail::seq_ref_size>::type sizes;
106 typedef typename result_of::fold<sizes, typename result_of::front<sizes>::type, detail::poly_min>::type type;
107 };
108 }
109
110 struct zip_view_tag;
111 struct fusion_sequence_tag;
112
113 template<typename Sequences>
114 struct zip_view : sequence_base< zip_view<Sequences> >
115 {
116 typedef typename result_of::remove<Sequences, unused_type const&>::type real_sequences;
117 BOOST_MPL_ASSERT((detail::all_references<Sequences>));
118 typedef typename detail::strictest_traversal<real_sequences>::type category;
119 typedef zip_view_tag fusion_tag;
120 typedef fusion_sequence_tag tag; // this gets picked up by MPL
121 typedef mpl::true_ is_view;
122 typedef typename fusion::result_of::as_vector<Sequences>::type sequences;
123 typedef typename detail::min_size<real_sequences>::type size;
124
125 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
126 zip_view(
127 const Sequences& seqs)
128 : sequences_(seqs)
129 {}
130
131 sequences sequences_;
132 };
133}}
134
135#endif
136