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
42namespace 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