aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/cxxsupp/libcxx/include/__ranges/size.h
blob: 0e6d295651a3cc3b32070ab71efcc92e59d4f667 (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
// -*- 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_SIZE_H
#define _LIBCPP___RANGES_SIZE_H

#include <__concepts/class_or_enum.h>
#include <__config>
#include <__iterator/concepts.h>
#include <__iterator/iterator_traits.h>
#include <__ranges/access.h>
#include <__utility/auto_cast.h>
#include <concepts>
#include <cstddef>
#include <type_traits>

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

_LIBCPP_BEGIN_NAMESPACE_STD

#if _LIBCPP_STD_VER > 17

namespace ranges {
  template<class>
  inline constexpr bool disable_sized_range = false;
} // namespace ranges

// [range.prim.size]

namespace ranges {
namespace __size {
void size(auto&) = delete;
void size(const auto&) = delete;

template <class _Tp>
concept __size_enabled = !disable_sized_range<remove_cvref_t<_Tp>>;

template <class _Tp>
concept __member_size =
  __size_enabled<_Tp> &&
  __workaround_52970<_Tp> &&
  requires(_Tp&& __t) {
    { _LIBCPP_AUTO_CAST(__t.size()) } -> __integer_like;
  };

template <class _Tp>
concept __unqualified_size =
  __size_enabled<_Tp> &&
  !__member_size<_Tp> &&
  __class_or_enum<remove_cvref_t<_Tp>> &&
  requires(_Tp&& __t) {
    { _LIBCPP_AUTO_CAST(size(__t)) } -> __integer_like;
  };

template <class _Tp>
concept __difference =
  !__member_size<_Tp> &&
  !__unqualified_size<_Tp> &&
  __class_or_enum<remove_cvref_t<_Tp>> &&
  requires(_Tp&& __t) {
    { ranges::begin(__t) } -> forward_iterator;
    { ranges::end(__t) } -> sized_sentinel_for<decltype(ranges::begin(declval<_Tp>()))>;
  };

struct __fn {

  // `[range.prim.size]`: the array case (for rvalues).
  template <class _Tp, size_t _Sz>
  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr size_t operator()(_Tp (&&)[_Sz]) const noexcept {
    return _Sz;
  }

  // `[range.prim.size]`: the array case (for lvalues).
  template <class _Tp, size_t _Sz>
  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr size_t operator()(_Tp (&)[_Sz]) const noexcept {
    return _Sz;
  }

  // `[range.prim.size]`: `auto(t.size())` is a valid expression.
  template <__member_size _Tp>
  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr __integer_like auto operator()(_Tp&& __t) const
      noexcept(noexcept(_LIBCPP_AUTO_CAST(__t.size()))) {
    return _LIBCPP_AUTO_CAST(__t.size());
  }

  // `[range.prim.size]`: `auto(size(t))` is a valid expression.
  template <__unqualified_size _Tp>
  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr __integer_like auto operator()(_Tp&& __t) const
      noexcept(noexcept(_LIBCPP_AUTO_CAST(size(__t)))) {
    return _LIBCPP_AUTO_CAST(size(__t));
  }

  // [range.prim.size]: the `to-unsigned-like` case.
  template <__difference _Tp>
  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const
    noexcept(noexcept(std::__to_unsigned_like(ranges::end(__t) - ranges::begin(__t))))
    -> decltype(      std::__to_unsigned_like(ranges::end(__t) - ranges::begin(__t)))
    { return          std::__to_unsigned_like(ranges::end(__t) - ranges::begin(__t));
  }
};

} // namespace __size

inline namespace __cpo {
  inline constexpr auto size = __size::__fn{};
} // namespace __cpo
} // namespace ranges

// [range.prim.ssize]

namespace ranges {
namespace __ssize {
struct __fn {
  template<class _Tp>
    requires requires (_Tp&& __t) { ranges::size(__t); }
  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr integral auto operator()(_Tp&& __t) const
    noexcept(noexcept(ranges::size(__t))) {
    using _Signed = make_signed_t<decltype(ranges::size(__t))>;
    if constexpr (sizeof(ptrdiff_t) > sizeof(_Signed))
      return static_cast<ptrdiff_t>(ranges::size(__t));
    else
      return static_cast<_Signed>(ranges::size(__t));
  }
};
} // namespace __ssize

inline namespace __cpo {
  inline constexpr auto ssize = __ssize::__fn{};
} // namespace __cpo
} // namespace ranges

#endif // _LIBCPP_STD_VER > 17

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___RANGES_SIZE_H