1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef _LIBCPP___ITERATOR_MOVE_SENTINEL_H
10#define _LIBCPP___ITERATOR_MOVE_SENTINEL_H
11
12#include <__concepts/assignable.h>
13#include <__concepts/convertible_to.h>
14#include <__concepts/semiregular.h>
15#include <__config>
16#include <__utility/move.h>
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#if _LIBCPP_STD_VER >= 20
28
29template <semiregular _Sent>
30class move_sentinel {
31public:
32 _LIBCPP_HIDE_FROM_ABI move_sentinel() = default;
33
34 _LIBCPP_HIDE_FROM_ABI constexpr explicit move_sentinel(_Sent __s) : __last_(std::move(__s)) {}
35
36 template <class _S2>
37 requires convertible_to<const _S2&, _Sent>
38 _LIBCPP_HIDE_FROM_ABI constexpr move_sentinel(const move_sentinel<_S2>& __s) : __last_(__s.base()) {}
39
40 template <class _S2>
41 requires assignable_from<_Sent&, const _S2&>
42 _LIBCPP_HIDE_FROM_ABI constexpr move_sentinel& operator=(const move_sentinel<_S2>& __s) {
43 __last_ = __s.base();
44 return *this;
45 }
46
47 _LIBCPP_HIDE_FROM_ABI constexpr _Sent base() const { return __last_; }
48
49private:
50 _Sent __last_ = _Sent();
51};
52
53_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(move_sentinel);
54
55#endif // _LIBCPP_STD_VER >= 20
56
57_LIBCPP_END_NAMESPACE_STD
58
59_LIBCPP_POP_MACROS
60
61#endif // _LIBCPP___ITERATOR_MOVE_SENTINEL_H
62