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 #include <__utility/forward.h> 14 #include <__utility/move.h> 15 #include <type_traits> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 #pragma GCC system_header 19 #endif 20 21 _LIBCPP_PUSH_MACROS 22 #include <__undef_macros> 23 24 _LIBCPP_BEGIN_NAMESPACE_STD 25 26 #if _LIBCPP_STD_VER > 14 27 template <class _Tp> 28 _LIBCPP_NODISCARD_EXT constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; } 29 30 template <class _Tp> 31 void as_const(const _Tp&&) = delete; 32 #endif 33 34 _LIBCPP_END_NAMESPACE_STD 35 36 _LIBCPP_POP_MACROS 37 38 #endif // _LIBCPP___UTILITY_AS_CONST_H 39