1 // -*- C++ -*- 2 //===----------------- __utility/to_underlying.h --------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___UTILITY_TO_UNDERLYING_H 11 #define _LIBCPP___UTILITY_TO_UNDERLYING_H 12 13 #include <__config> 14 #include <type_traits> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 #pragma GCC system_header 18 #endif 19 20 _LIBCPP_PUSH_MACROS 21 #include <__undef_macros> 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 #ifndef _LIBCPP_CXX03_LANG 26 template <class _Tp> 27 _LIBCPP_INLINE_VISIBILITY constexpr typename underlying_type<_Tp>::type 28 __to_underlying(_Tp __val) noexcept { 29 return static_cast<typename underlying_type<_Tp>::type>(__val); 30 } 31 #endif // !_LIBCPP_CXX03_LANG 32 33 #if _LIBCPP_STD_VER > 20 34 template <class _Tp> 35 _LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY constexpr underlying_type_t<_Tp> 36 to_underlying(_Tp __val) noexcept { 37 return _VSTD::__to_underlying(__val); 38 } 39 #endif 40 41 _LIBCPP_END_NAMESPACE_STD 42 43 _LIBCPP_POP_MACROS 44 45 #endif // _LIBCPP___UTILITY_TO_UNDERLYING_H 46