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
|
// -*- 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_TAKE_VIEW_H
#define _LIBCPP___RANGES_TAKE_VIEW_H
#include <__algorithm/ranges_min.h>
#include <__config>
#include <__iterator/concepts.h>
#include <__iterator/counted_iterator.h>
#include <__iterator/default_sentinel.h>
#include <__iterator/iterator_traits.h>
#include <__ranges/access.h>
#include <__ranges/all.h>
#include <__ranges/concepts.h>
#include <__ranges/enable_borrowed_range.h>
#include <__ranges/size.h>
#include <__ranges/view_interface.h>
#include <__utility/move.h>
#include <concepts>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
namespace ranges {
template<view _View>
class take_view : public view_interface<take_view<_View>> {
_LIBCPP_NO_UNIQUE_ADDRESS _View __base_ = _View();
range_difference_t<_View> __count_ = 0;
template<bool> class __sentinel;
public:
_LIBCPP_HIDE_FROM_ABI
take_view() requires default_initializable<_View> = default;
_LIBCPP_HIDE_FROM_ABI
constexpr take_view(_View __base, range_difference_t<_View> __count)
: __base_(std::move(__base)), __count_(__count) {}
_LIBCPP_HIDE_FROM_ABI
constexpr _View base() const& requires copy_constructible<_View> { return __base_; }
_LIBCPP_HIDE_FROM_ABI
constexpr _View base() && { return std::move(__base_); }
_LIBCPP_HIDE_FROM_ABI
constexpr auto begin() requires (!__simple_view<_View>) {
if constexpr (sized_range<_View>) {
if constexpr (random_access_range<_View>) {
return ranges::begin(__base_);
} else {
using _DifferenceT = range_difference_t<_View>;
auto __size = size();
return counted_iterator(ranges::begin(__base_), static_cast<_DifferenceT>(__size));
}
} else {
return counted_iterator(ranges::begin(__base_), __count_);
}
}
_LIBCPP_HIDE_FROM_ABI
constexpr auto begin() const requires range<const _View> {
if constexpr (sized_range<const _View>) {
if constexpr (random_access_range<const _View>) {
return ranges::begin(__base_);
} else {
using _DifferenceT = range_difference_t<const _View>;
auto __size = size();
return counted_iterator(ranges::begin(__base_), static_cast<_DifferenceT>(__size));
}
} else {
return counted_iterator(ranges::begin(__base_), __count_);
}
}
_LIBCPP_HIDE_FROM_ABI
constexpr auto end() requires (!__simple_view<_View>) {
if constexpr (sized_range<_View>) {
if constexpr (random_access_range<_View>) {
return ranges::begin(__base_) + size();
} else {
return default_sentinel;
}
} else {
return __sentinel<false>{ranges::end(__base_)};
}
}
_LIBCPP_HIDE_FROM_ABI
constexpr auto end() const requires range<const _View> {
if constexpr (sized_range<const _View>) {
if constexpr (random_access_range<const _View>) {
return ranges::begin(__base_) + size();
} else {
return default_sentinel;
}
} else {
return __sentinel<true>{ranges::end(__base_)};
}
}
_LIBCPP_HIDE_FROM_ABI
constexpr auto size() requires sized_range<_View> {
auto __n = ranges::size(__base_);
return ranges::min(__n, static_cast<decltype(__n)>(__count_));
}
_LIBCPP_HIDE_FROM_ABI
constexpr auto size() const requires sized_range<const _View> {
auto __n = ranges::size(__base_);
return ranges::min(__n, static_cast<decltype(__n)>(__count_));
}
};
template<view _View>
template<bool _Const>
class take_view<_View>::__sentinel {
using _Base = __maybe_const<_Const, _View>;
template<bool _OtherConst>
using _Iter = counted_iterator<iterator_t<__maybe_const<_OtherConst, _View>>>;
_LIBCPP_NO_UNIQUE_ADDRESS sentinel_t<_Base> __end_ = sentinel_t<_Base>();
template<bool>
friend class take_view<_View>::__sentinel;
public:
_LIBCPP_HIDE_FROM_ABI
__sentinel() = default;
_LIBCPP_HIDE_FROM_ABI
constexpr explicit __sentinel(sentinel_t<_Base> __end) : __end_(std::move(__end)) {}
_LIBCPP_HIDE_FROM_ABI
constexpr __sentinel(__sentinel<!_Const> __s)
requires _Const && convertible_to<sentinel_t<_View>, sentinel_t<_Base>>
: __end_(std::move(__s.__end_)) {}
_LIBCPP_HIDE_FROM_ABI
constexpr sentinel_t<_Base> base() const { return __end_; }
_LIBCPP_HIDE_FROM_ABI
friend constexpr bool operator==(const _Iter<_Const>& __lhs, const __sentinel& __rhs) {
return __lhs.count() == 0 || __lhs.base() == __rhs.__end_;
}
template<bool _OtherConst = !_Const>
requires sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>>
_LIBCPP_HIDE_FROM_ABI
friend constexpr bool operator==(const _Iter<_Const>& __lhs, const __sentinel& __rhs) {
return __lhs.count() == 0 || __lhs.base() == __rhs.__end_;
}
};
template<class _Range>
take_view(_Range&&, range_difference_t<_Range>) -> take_view<views::all_t<_Range>>;
template<class _Tp>
inline constexpr bool enable_borrowed_range<take_view<_Tp>> = enable_borrowed_range<_Tp>;
} // namespace ranges
#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___RANGES_TAKE_VIEW_H
|
