summaryrefslogtreecommitdiffstats
path: root/libcxx/include/__ranges/access.h
blob: 168e0304f5091312a14bf64891a1b693e084d4fe (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___RANGES_ACCESS_H
#define _LIBCPP___RANGES_ACCESS_H

#include <__concepts/class_or_enum.h>
#include <__config>
#include <__iterator/concepts.h>
#include <__iterator/readable_traits.h>
#include <__ranges/enable_borrowed_range.h>
#include <__utility/as_const.h>
#include <__utility/auto_cast.h>
#include <concepts>
#include <type_traits>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

#if !defined(_LIBCPP_HAS_NO_CONCEPTS)

namespace ranges {
  template <class _Tp>
  concept __can_borrow =
    is_lvalue_reference_v<_Tp> || enable_borrowed_range<remove_cvref_t<_Tp>>;
} // namespace ranges

// [range.access.begin]

namespace ranges {
namespace __begin {
  template <class _Tp>
  concept __member_begin =
    __can_borrow<_Tp> &&
    __workaround_52970<_Tp> &&
    requires(_Tp&& __t) {
      { _LIBCPP_AUTO_CAST(__t.begin()) } -> input_or_output_iterator;
    };

  void begin(auto&) = delete;
  void begin(const auto&) = delete;

  template <class _Tp>
  concept __unqualified_begin =
    !__member_begin<_Tp> &&
    __can_borrow<_Tp> &&
    __class_or_enum<remove_cvref_t<_Tp>> &&
    requires(_Tp && __t) {
      { _LIBCPP_AUTO_CAST(begin(__t)) } -> input_or_output_iterator;
    };

  struct __fn {
    template <class _Tp>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp (&__t)[]) const noexcept
      requires (sizeof(_Tp) != 0)  // Disallow incomplete element types.
    {
      return __t + 0;
    }

    template <class _Tp, size_t _Np>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp (&__t)[_Np]) const noexcept
      requires (sizeof(_Tp) != 0)  // Disallow incomplete element types.
    {
      return __t + 0;
    }

    template <class _Tp>
      requires __member_begin<_Tp>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const
      noexcept(noexcept(_LIBCPP_AUTO_CAST(__t.begin())))
    {
      return _LIBCPP_AUTO_CAST(__t.begin());
    }

    template <class _Tp>
      requires __unqualified_begin<_Tp>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const
      noexcept(noexcept(_LIBCPP_AUTO_CAST(begin(__t))))
    {
      return _LIBCPP_AUTO_CAST(begin(__t));
    }

    void operator()(auto&&) const = delete;
  };
} // namespace __begin

inline namespace __cpo {
  inline constexpr auto begin = __begin::__fn{};
} // namespace __cpo
} // namespace ranges

// [range.range]

namespace ranges {
  template <class _Tp>
  using iterator_t = decltype(ranges::begin(declval<_Tp&>()));
} // namespace ranges

// [range.access.end]

namespace ranges {
namespace __end {
  template <class _Tp>
  concept __member_end =
    __can_borrow<_Tp> &&
    __workaround_52970<_Tp> &&
    requires(_Tp&& __t) {
      typename iterator_t<_Tp>;
      { _LIBCPP_AUTO_CAST(__t.end()) } -> sentinel_for<iterator_t<_Tp>>;
    };

  void end(auto&) = delete;
  void end(const auto&) = delete;

  template <class _Tp>
  concept __unqualified_end =
    !__member_end<_Tp> &&
    __can_borrow<_Tp> &&
    __class_or_enum<remove_cvref_t<_Tp>> &&
    requires(_Tp && __t) {
      typename iterator_t<_Tp>;
      { _LIBCPP_AUTO_CAST(end(__t)) } -> sentinel_for<iterator_t<_Tp>>;
    };

  class __fn {
  public:
    template <class _Tp, size_t _Np>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp (&__t)[_Np]) const noexcept
      requires (sizeof(_Tp) != 0)  // Disallow incomplete element types.
    {
      return __t + _Np;
    }

    template <class _Tp>
      requires __member_end<_Tp>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const
      noexcept(noexcept(_LIBCPP_AUTO_CAST(__t.end())))
    {
      return _LIBCPP_AUTO_CAST(__t.end());
    }

    template <class _Tp>
      requires __unqualified_end<_Tp>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const
      noexcept(noexcept(_LIBCPP_AUTO_CAST(end(__t))))
    {
      return _LIBCPP_AUTO_CAST(end(__t));
    }

    void operator()(auto&&) const = delete;
  };
} // namespace __end

inline namespace __cpo {
  inline constexpr auto end = __end::__fn{};
} // namespace __cpo
} // namespace ranges

// [range.access.cbegin]

namespace ranges {
namespace __cbegin {
  struct __fn {
    template <class _Tp>
      requires is_lvalue_reference_v<_Tp&&>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
    constexpr auto operator()(_Tp&& __t) const
      noexcept(noexcept(ranges::begin(static_cast<const remove_reference_t<_Tp>&>(__t))))
      -> decltype(      ranges::begin(static_cast<const remove_reference_t<_Tp>&>(__t)))
      { return          ranges::begin(static_cast<const remove_reference_t<_Tp>&>(__t)); }

    template <class _Tp>
      requires is_rvalue_reference_v<_Tp&&>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
    constexpr auto operator()(_Tp&& __t) const
      noexcept(noexcept(ranges::begin(static_cast<const _Tp&&>(__t))))
      -> decltype(      ranges::begin(static_cast<const _Tp&&>(__t)))
      { return          ranges::begin(static_cast<const _Tp&&>(__t)); }
  };
} // namespace __cbegin

inline namespace __cpo {
  inline constexpr auto cbegin = __cbegin::__fn{};
} // namespace __cpo
} // namespace ranges

// [range.access.cend]

namespace ranges {
namespace __cend {
  struct __fn {
    template <class _Tp>
      requires is_lvalue_reference_v<_Tp&&>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
    constexpr auto operator()(_Tp&& __t) const
      noexcept(noexcept(ranges::end(static_cast<const remove_reference_t<_Tp>&>(__t))))
      -> decltype(      ranges::end(static_cast<const remove_reference_t<_Tp>&>(__t)))
      { return          ranges::end(static_cast<const remove_reference_t<_Tp>&>(__t)); }

    template <class _Tp>
      requires is_rvalue_reference_v<_Tp&&>
    [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
    constexpr auto operator()(_Tp&& __t) const
      noexcept(noexcept(ranges::end(static_cast<const _Tp&&>(__t))))
      -> decltype(      ranges::end(static_cast<const _Tp&&>(__t)))
      { return          ranges::end(static_cast<const _Tp&&>(__t)); }
  };
} // namespace __cend

inline namespace __cpo {
  inline constexpr auto cend = __cend::__fn{};
} // namespace __cpo
} // namespace ranges

#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___RANGES_ACCESS_H