1// -*- C++ -*-
2//===--------------------- __ranges/concepts.h ----------------------------===//
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 <__config>
13#include <__iterator/concepts.h>
14#include <__ranges/access.h>
15#include <__ranges/size.h>
16#include <type_traits>
17
18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19#pragma GCC system_header
20#endif
21
22_LIBCPP_PUSH_MACROS
23#include <__undef_macros>
24
25_LIBCPP_BEGIN_NAMESPACE_STD
26
27// clang-format off
28
29#if !defined(_LIBCPP_HAS_NO_RANGES)
30
31namespace ranges {
32  // [range.range]
33  template <class _Tp>
34  concept range = requires(_Tp& __t) {
35    ranges::begin(__t); // sometimes equality-preserving
36    ranges::end(__t);
37  };
38
39  template<class _Range>
40  concept borrowed_range = range<_Range> &&
41    (is_lvalue_reference_v<_Range> || enable_borrowed_range<remove_cvref_t<_Range>>);
42
43  // `iterator_t` defined in <__ranges/access.h>
44
45  template <range _Rp>
46  using sentinel_t = decltype(ranges::end(declval<_Rp&>()));
47
48  template <range _Rp>
49  using range_difference_t = iter_difference_t<iterator_t<_Rp> >;
50
51  template <range _Rp>
52  using range_value_t = iter_value_t<iterator_t<_Rp> >;
53
54  template <range _Rp>
55  using range_reference_t = iter_reference_t<iterator_t<_Rp> >;
56
57  template <range _Rp>
58  using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<_Rp> >;
59
60  // [range.sized]
61  template <class _Tp>
62  concept sized_range = range<_Tp> && requires(_Tp& __t) { ranges::size(__t); };
63
64  // `disable_sized_range` defined in `<__ranges/size.h>`
65
66  // [range.refinements], other range refinements
67  template <class _Tp>
68  concept input_range = range<_Tp> && input_iterator<iterator_t<_Tp> >;
69
70  template <class _Tp>
71  concept forward_range = input_range<_Tp> && forward_iterator<iterator_t<_Tp> >;
72
73  template <class _Tp>
74  concept bidirectional_range = forward_range<_Tp> && bidirectional_iterator<iterator_t<_Tp> >;
75
76  template <class _Tp>
77  concept random_access_range =
78      bidirectional_range<_Tp> && random_access_iterator<iterator_t<_Tp> >;
79
80  template <class _Tp>
81  concept common_range = range<_Tp> && same_as<iterator_t<_Tp>, sentinel_t<_Tp> >;
82} // namespace ranges
83
84#endif // !defined(_LIBCPP_HAS_NO_RANGES)
85
86// clang-format on
87
88_LIBCPP_END_NAMESPACE_STD
89
90_LIBCPP_POP_MACROS
91
92#endif // _LIBCPP___RANGES_CONCEPTS_H
93