1fe6060f1SDimitry Andric //===----------------------------------------------------------------------===// 2fe6060f1SDimitry Andric // 3fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6fe6060f1SDimitry Andric // 7fe6060f1SDimitry Andric //===----------------------------------------------------------------------===// 8fe6060f1SDimitry Andric 9fe6060f1SDimitry Andric #ifndef _LIBCPP___UTILITY_AS_CONST_H 10fe6060f1SDimitry Andric #define _LIBCPP___UTILITY_AS_CONST_H 11fe6060f1SDimitry Andric 12fe6060f1SDimitry Andric #include <__config> 13bdd1243dSDimitry Andric #include <__type_traits/add_const.h> 14fe6060f1SDimitry Andric #include <__utility/forward.h> 15fe6060f1SDimitry Andric #include <__utility/move.h> 16fe6060f1SDimitry Andric 17fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18fe6060f1SDimitry Andric # pragma GCC system_header 19fe6060f1SDimitry Andric #endif 20fe6060f1SDimitry Andric 21fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 22fe6060f1SDimitry Andric 2306c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 17 24fe6060f1SDimitry Andric template <class _Tp> as_const(_Tp & __t)25*0fca6ea1SDimitry Andric[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { 26cb14a3feSDimitry Andric return __t; 27cb14a3feSDimitry Andric } 28fe6060f1SDimitry Andric 29fe6060f1SDimitry Andric template <class _Tp> 30fe6060f1SDimitry Andric void as_const(const _Tp&&) = delete; 31fe6060f1SDimitry Andric #endif 32fe6060f1SDimitry Andric 33fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD 34fe6060f1SDimitry Andric 35fe6060f1SDimitry Andric #endif // _LIBCPP___UTILITY_AS_CONST_H 36