1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___RANGES_CONCEPTS_H 11 #define _LIBCPP___RANGES_CONCEPTS_H 12 13 #include <__concepts/constructible.h> 14 #include <__concepts/movable.h> 15 #include <__concepts/same_as.h> 16 #include <__config> 17 #include <__iterator/concepts.h> 18 #include <__iterator/incrementable_traits.h> 19 #include <__iterator/iter_move.h> 20 #include <__iterator/iterator_traits.h> 21 #include <__iterator/readable_traits.h> 22 #include <__ranges/access.h> 23 #include <__ranges/data.h> 24 #include <__ranges/enable_borrowed_range.h> 25 #include <__ranges/enable_view.h> 26 #include <__ranges/size.h> 27 #include <__type_traits/add_pointer.h> 28 #include <__type_traits/is_reference.h> 29 #include <__type_traits/remove_cvref.h> 30 #include <__type_traits/remove_reference.h> 31 #include <__utility/declval.h> 32 #include <initializer_list> 33 34 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 35 # pragma GCC system_header 36 #endif 37 38 _LIBCPP_BEGIN_NAMESPACE_STD 39 40 #if _LIBCPP_STD_VER > 17 41 42 namespace ranges { 43 44 // [range.range] 45 46 template <class _Tp> 47 concept range = requires(_Tp& __t) { 48 ranges::begin(__t); // sometimes equality-preserving 49 ranges::end(__t); 50 }; 51 52 template <class _Tp> 53 concept input_range = range<_Tp> && input_iterator<iterator_t<_Tp>>; 54 55 template<class _Range> 56 concept borrowed_range = range<_Range> && 57 (is_lvalue_reference_v<_Range> || enable_borrowed_range<remove_cvref_t<_Range>>); 58 59 // `iterator_t` defined in <__ranges/access.h> 60 61 template <range _Rp> 62 using sentinel_t = decltype(ranges::end(std::declval<_Rp&>())); 63 64 template <range _Rp> 65 using range_difference_t = iter_difference_t<iterator_t<_Rp>>; 66 67 template <range _Rp> 68 using range_value_t = iter_value_t<iterator_t<_Rp>>; 69 70 template <range _Rp> 71 using range_reference_t = iter_reference_t<iterator_t<_Rp>>; 72 73 template <range _Rp> 74 using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<_Rp>>; 75 76 // [range.sized] 77 template <class _Tp> 78 concept sized_range = range<_Tp> && requires(_Tp& __t) { ranges::size(__t); }; 79 80 template<sized_range _Rp> 81 using range_size_t = decltype(ranges::size(std::declval<_Rp&>())); 82 83 // `disable_sized_range` defined in `<__ranges/size.h>` 84 85 // [range.view], views 86 87 // `enable_view` defined in <__ranges/enable_view.h> 88 // `view_base` defined in <__ranges/enable_view.h> 89 90 template <class _Tp> 91 concept view = 92 range<_Tp> && 93 movable<_Tp> && 94 enable_view<_Tp>; 95 96 template <class _Range> 97 concept __simple_view = 98 view<_Range> && range<const _Range> && 99 same_as<iterator_t<_Range>, iterator_t<const _Range>> && 100 same_as<sentinel_t<_Range>, sentinel_t<const _Range>>; 101 102 // [range.refinements], other range refinements 103 template <class _Rp, class _Tp> 104 concept output_range = range<_Rp> && output_iterator<iterator_t<_Rp>, _Tp>; 105 106 template <class _Tp> 107 concept forward_range = input_range<_Tp> && forward_iterator<iterator_t<_Tp>>; 108 109 template <class _Tp> 110 concept bidirectional_range = forward_range<_Tp> && bidirectional_iterator<iterator_t<_Tp>>; 111 112 template <class _Tp> 113 concept random_access_range = 114 bidirectional_range<_Tp> && random_access_iterator<iterator_t<_Tp>>; 115 116 template<class _Tp> 117 concept contiguous_range = 118 random_access_range<_Tp> && 119 contiguous_iterator<iterator_t<_Tp>> && 120 requires(_Tp& __t) { 121 { ranges::data(__t) } -> same_as<add_pointer_t<range_reference_t<_Tp>>>; 122 }; 123 124 template <class _Tp> 125 concept common_range = range<_Tp> && same_as<iterator_t<_Tp>, sentinel_t<_Tp>>; 126 127 template <class _Tp> 128 inline constexpr bool __is_std_initializer_list = false; 129 130 template <class _Ep> 131 inline constexpr bool __is_std_initializer_list<initializer_list<_Ep>> = true; 132 133 template <class _Tp> 134 concept viewable_range = 135 range<_Tp> && 136 ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>) || 137 (!view<remove_cvref_t<_Tp>> && 138 (is_lvalue_reference_v<_Tp> || 139 (movable<remove_reference_t<_Tp>> && !__is_std_initializer_list<remove_cvref_t<_Tp>>)))); 140 141 } // namespace ranges 142 143 #endif // _LIBCPP_STD_VER > 17 144 145 _LIBCPP_END_NAMESPACE_STD 146 147 #endif // _LIBCPP___RANGES_CONCEPTS_H 148