1349cc55cSDimitry Andric // -*- C++ -*- 2349cc55cSDimitry Andric //===----------------------------------------------------------------------===// 3349cc55cSDimitry Andric // 4349cc55cSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5349cc55cSDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 6349cc55cSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7349cc55cSDimitry Andric // 8349cc55cSDimitry Andric //===----------------------------------------------------------------------===// 9349cc55cSDimitry Andric 10349cc55cSDimitry Andric #ifndef _LIBCPP___ITERATOR_UNREACHABLE_SENTINEL_H 11349cc55cSDimitry Andric #define _LIBCPP___ITERATOR_UNREACHABLE_SENTINEL_H 12349cc55cSDimitry Andric 13349cc55cSDimitry Andric #include <__config> 14349cc55cSDimitry Andric #include <__iterator/concepts.h> 15349cc55cSDimitry Andric 16349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17349cc55cSDimitry Andric # pragma GCC system_header 18349cc55cSDimitry Andric #endif 19349cc55cSDimitry Andric 20349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 21349cc55cSDimitry Andric 2206c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20 23349cc55cSDimitry Andric 24349cc55cSDimitry Andric struct unreachable_sentinel_t { 25349cc55cSDimitry Andric template <weakly_incrementable _Iter> 26*cb14a3feSDimitry Andric _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(unreachable_sentinel_t, const _Iter&) noexcept { 27349cc55cSDimitry Andric return false; 28349cc55cSDimitry Andric } 29349cc55cSDimitry Andric }; 30349cc55cSDimitry Andric 31349cc55cSDimitry Andric inline constexpr unreachable_sentinel_t unreachable_sentinel{}; 32349cc55cSDimitry Andric 3306c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20 34349cc55cSDimitry Andric 35349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD 36349cc55cSDimitry Andric 37349cc55cSDimitry Andric #endif // _LIBCPP___ITERATOR_UNREACHABLE_SENTINEL_H 38