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___UTILITY_AS_CONST_H 10 #define _LIBCPP___UTILITY_AS_CONST_H 11 12 #include <__config> 13 14 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 15 # pragma GCC system_header 16 #endif 17 18 _LIBCPP_BEGIN_NAMESPACE_STD 19 20 #if _LIBCPP_STD_VER >= 17 21 template <class _Tp> 22 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Tp& as_const(_Tp& __t) noexcept { 23 return __t; 24 } 25 26 template <class _Tp> 27 void as_const(const _Tp&&) = delete; 28 #endif 29 30 _LIBCPP_END_NAMESPACE_STD 31 32 #endif // _LIBCPP___UTILITY_AS_CONST_H 33