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 43 namespace 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 zip_viewboost::fusion::zip_view126 zip_view( 127 const Sequences& seqs) 128 : sequences_(seqs) 129 {} 130 131 sequences sequences_; 132 }; 133 }} 134 135 #endif 136