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 29 template <semiregular _Sent> 30 class _LIBCPP_TEMPLATE_VIS move_sentinel { 31 public: 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 49 private: 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