1 /*============================================================================= 2 Copyright (c) 2001-2011 Joel de Guzman 3 Copyright (c) 2005 Eric Niebler 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_CONS_ITERATOR_07172005_0849) 9 #define FUSION_CONS_ITERATOR_07172005_0849 10 11 #include <boost/fusion/support/config.hpp> 12 #include <boost/type_traits/add_const.hpp> 13 #include <boost/fusion/support/iterator_base.hpp> 14 #include <boost/fusion/container/list/detail/deref_impl.hpp> 15 #include <boost/fusion/container/list/detail/next_impl.hpp> 16 #include <boost/fusion/container/list/detail/value_of_impl.hpp> 17 #include <boost/fusion/container/list/detail/equal_to_impl.hpp> 18 #include <boost/fusion/container/list/list_fwd.hpp> 19 20 namespace boost { namespace fusion 21 { 22 struct nil_; 23 struct cons_iterator_tag; 24 struct forward_traversal_tag; 25 26 template <typename Cons> 27 struct cons_iterator_identity; 28 29 template <typename Cons = nil_> 30 struct cons_iterator : iterator_base<cons_iterator<Cons> > 31 { 32 typedef cons_iterator_tag fusion_tag; 33 typedef forward_traversal_tag category; 34 typedef Cons cons_type; 35 typedef cons_iterator_identity< 36 typename add_const<Cons>::type> 37 identity; 38 39 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED cons_iteratorboost::fusion::cons_iterator40 explicit cons_iterator(cons_type& in_cons) BOOST_NOEXCEPT 41 : cons(in_cons) {} 42 43 cons_type& cons; 44 45 // silence MSVC warning C4512: assignment operator could not be generated 46 BOOST_DELETED_FUNCTION(cons_iterator& operator= (cons_iterator const&)) 47 }; 48 49 struct nil_iterator : iterator_base<nil_iterator> 50 { 51 typedef forward_traversal_tag category; 52 typedef cons_iterator_tag fusion_tag; 53 typedef nil_ cons_type; 54 typedef cons_iterator_identity< 55 add_const<nil_>::type> 56 identity; 57 58 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED nil_iteratorboost::fusion::nil_iterator59 nil_iterator() BOOST_NOEXCEPT {} 60 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED nil_iteratorboost::fusion::nil_iterator61 explicit nil_iterator(nil_ const&) BOOST_NOEXCEPT {} 62 }; 63 64 template <> 65 struct cons_iterator<nil_> : nil_iterator 66 { 67 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED cons_iteratorboost::fusion::cons_iterator68 cons_iterator() BOOST_NOEXCEPT {} 69 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED cons_iteratorboost::fusion::cons_iterator70 explicit cons_iterator(nil_ const&) BOOST_NOEXCEPT {} 71 }; 72 73 template <> 74 struct cons_iterator<nil_ const> : nil_iterator 75 { 76 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED cons_iteratorboost::fusion::cons_iterator77 cons_iterator() BOOST_NOEXCEPT {} 78 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED cons_iteratorboost::fusion::cons_iterator79 explicit cons_iterator(nil_ const&) BOOST_NOEXCEPT {} 80 }; 81 82 template <> 83 struct cons_iterator<list<> > : nil_iterator 84 { 85 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED 86 cons_iterator() BOOST_NOEXCEPT {} 87 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED 88 explicit cons_iterator(nil_ const&) BOOST_NOEXCEPT {} 89 }; 90 91 template <> 92 struct cons_iterator<list<> const> : nil_iterator 93 { 94 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED 95 cons_iterator() BOOST_NOEXCEPT {} 96 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED 97 explicit cons_iterator(nil_ const&) BOOST_NOEXCEPT {} 98 }; 99 }} 100 101 #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408 102 namespace std 103 { 104 template <typename Cons> 105 struct iterator_traits< ::boost::fusion::cons_iterator<Cons> > 106 { }; 107 } 108 #endif 109 110 #endif 111