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 _LIBCPP_STD_VER > 17 36 37 namespace ranges { 38 39 // [range.range] 40 41 template <class _Tp> 42 concept range = requires(_Tp& __t) { 43 ranges::begin(__t); // sometimes equality-preserving 44 ranges::end(__t); 45 }; 46 47 template <class _Tp> 48 concept input_range = range<_Tp> && input_iterator<iterator_t<_Tp>>; 49 50 template<class _Range> 51 concept borrowed_range = range<_Range> && 52 (is_lvalue_reference_v<_Range> || enable_borrowed_range<remove_cvref_t<_Range>>); 53 54 // `iterator_t` defined in <__ranges/access.h> 55 56 template <range _Rp> 57 using sentinel_t = decltype(ranges::end(declval<_Rp&>())); 58 59 template <range _Rp> 60 using range_difference_t = iter_difference_t<iterator_t<_Rp>>; 61 62 template <range _Rp> 63 using range_value_t = iter_value_t<iterator_t<_Rp>>; 64 65 template <range _Rp> 66 using range_reference_t = iter_reference_t<iterator_t<_Rp>>; 67 68 template <range _Rp> 69 using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<_Rp>>; 70 71 // [range.sized] 72 template <class _Tp> 73 concept sized_range = range<_Tp> && requires(_Tp& __t) { ranges::size(__t); }; 74 75 template<sized_range _Rp> 76 using range_size_t = decltype(ranges::size(declval<_Rp&>())); 77 78 // `disable_sized_range` defined in `<__ranges/size.h>` 79 80 // [range.view], views 81 82 // `enable_view` defined in <__ranges/enable_view.h> 83 // `view_base` defined in <__ranges/enable_view.h> 84 85 template <class _Tp> 86 concept view = 87 range<_Tp> && 88 movable<_Tp> && 89 enable_view<_Tp>; 90 91 template <class _Range> 92 concept __simple_view = 93 view<_Range> && range<const _Range> && 94 same_as<iterator_t<_Range>, iterator_t<const _Range>> && 95 same_as<sentinel_t<_Range>, sentinel_t<const _Range>>; 96 97 // [range.refinements], other range refinements 98 template <class _Rp, class _Tp> 99 concept output_range = range<_Rp> && output_iterator<iterator_t<_Rp>, _Tp>; 100 101 template <class _Tp> 102 concept forward_range = input_range<_Tp> && forward_iterator<iterator_t<_Tp>>; 103 104 template <class _Tp> 105 concept bidirectional_range = forward_range<_Tp> && bidirectional_iterator<iterator_t<_Tp>>; 106 107 template <class _Tp> 108 concept random_access_range = 109 bidirectional_range<_Tp> && random_access_iterator<iterator_t<_Tp>>; 110 111 template<class _Tp> 112 concept contiguous_range = 113 random_access_range<_Tp> && 114 contiguous_iterator<iterator_t<_Tp>> && 115 requires(_Tp& __t) { 116 { ranges::data(__t) } -> same_as<add_pointer_t<range_reference_t<_Tp>>>; 117 }; 118 119 template <class _Tp> 120 concept common_range = range<_Tp> && same_as<iterator_t<_Tp>, sentinel_t<_Tp>>; 121 122 template <class _Tp> 123 inline constexpr bool __is_std_initializer_list = false; 124 125 template <class _Ep> 126 inline constexpr bool __is_std_initializer_list<initializer_list<_Ep>> = true; 127 128 template <class _Tp> 129 concept viewable_range = 130 range<_Tp> && 131 ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>) || 132 (!view<remove_cvref_t<_Tp>> && 133 (is_lvalue_reference_v<_Tp> || 134 (movable<remove_reference_t<_Tp>> && !__is_std_initializer_list<remove_cvref_t<_Tp>>)))); 135 136 } // namespace ranges 137 138 #endif // _LIBCPP_STD_VER > 17 139 140 _LIBCPP_END_NAMESPACE_STD 141 142 #endif // _LIBCPP___RANGES_CONCEPTS_H 143