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