2 //===--------------------- __ranges/concepts.h ----------------------------===//
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
8 //===----------------------------------------------------------------------===//
9 #ifndef _LIBCPP___RANGES_CONCEPTS_H
10 #define _LIBCPP___RANGES_CONCEPTS_H
13 #include <__iterator/concepts.h>
14 #include <__iterator/incrementable_traits.h>
15 #include <__iterator/iter_move.h>
16 #include <__iterator/iterator_traits.h>
17 #include <__iterator/readable_traits.h>
18 #include <__ranges/access.h>
19 #include <__ranges/enable_borrowed_range.h>
20 #include <__ranges/data.h>
21 #include <__ranges/enable_view.h>
22 #include <__ranges/size.h>
24 #include <type_traits>
26 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
27 #pragma GCC system_header
31 #include <__undef_macros>
33 _LIBCPP_BEGIN_NAMESPACE_STD
37 #if !defined(_LIBCPP_HAS_NO_RANGES)
42 concept range = requires(_Tp& __t) {
43 ranges::begin(__t); // sometimes equality-preserving
47 template<class _Range>
48 concept borrowed_range = range<_Range> &&
49 (is_lvalue_reference_v<_Range> || enable_borrowed_range<remove_cvref_t<_Range>>);
51 // `iterator_t` defined in <__ranges/access.h>
54 using sentinel_t = decltype(ranges::end(declval<_Rp&>()));
57 using range_difference_t = iter_difference_t<iterator_t<_Rp>>;
60 using range_value_t = iter_value_t<iterator_t<_Rp>>;
63 using range_reference_t = iter_reference_t<iterator_t<_Rp>>;
66 using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<_Rp>>;
70 concept sized_range = range<_Tp> && requires(_Tp& __t) { ranges::size(__t); };
72 template<sized_range _Rp>
73 using range_size_t = decltype(ranges::size(declval<_Rp&>()));
75 // `disable_sized_range` defined in `<__ranges/size.h>`
77 // [range.view], views
79 // `enable_view` defined in <__ranges/enable_view.h>
80 // `view_base` defined in <__ranges/enable_view.h>
88 template<class _Range>
89 concept __simple_view =
90 view<_Range> && range<const _Range> &&
91 same_as<iterator_t<_Range>, iterator_t<const _Range>> &&
92 same_as<sentinel_t<_Range>, iterator_t<const _Range>>;
94 // [range.refinements], other range refinements
95 template <class _Rp, class _Tp>
96 concept output_range = range<_Rp> && output_iterator<iterator_t<_Rp>, _Tp>;
99 concept input_range = range<_Tp> && input_iterator<iterator_t<_Tp>>;
102 concept forward_range = input_range<_Tp> && forward_iterator<iterator_t<_Tp>>;
105 concept bidirectional_range = forward_range<_Tp> && bidirectional_iterator<iterator_t<_Tp>>;
108 concept random_access_range =
109 bidirectional_range<_Tp> && random_access_iterator<iterator_t<_Tp>>;
112 concept contiguous_range =
113 random_access_range<_Tp> &&
114 contiguous_iterator<iterator_t<_Tp>> &&
116 { ranges::data(__t) } -> same_as<add_pointer_t<range_reference_t<_Tp>>>;
120 concept common_range = range<_Tp> && same_as<iterator_t<_Tp>, sentinel_t<_Tp>>;
123 concept viewable_range =
125 (view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>) ||
126 (!view<remove_cvref_t<_Tp>> && borrowed_range<_Tp>)
128 } // namespace ranges
130 #endif // !defined(_LIBCPP_HAS_NO_RANGES)
134 _LIBCPP_END_NAMESPACE_STD
138 #endif // _LIBCPP___RANGES_CONCEPTS_H