xref: /freebsd/contrib/llvm-project/libcxx/include/__utility/to_underlying.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
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/underlying_type.h>
15 
16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17 #  pragma GCC system_header
18 #endif
19 
20 _LIBCPP_BEGIN_NAMESPACE_STD
21 
22 #ifndef _LIBCPP_CXX03_LANG
23 template <class _Tp>
__to_underlying(_Tp __val)24 _LIBCPP_HIDE_FROM_ABI constexpr typename underlying_type<_Tp>::type __to_underlying(_Tp __val) noexcept {
25   return static_cast<typename underlying_type<_Tp>::type>(__val);
26 }
27 #endif // !_LIBCPP_CXX03_LANG
28 
29 #if _LIBCPP_STD_VER >= 23
30 template <class _Tp>
to_underlying(_Tp __val)31 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr underlying_type_t<_Tp> to_underlying(_Tp __val) noexcept {
32   return std::__to_underlying(__val);
33 }
34 #endif
35 
36 _LIBCPP_END_NAMESPACE_STD
37 
38 #endif // _LIBCPP___UTILITY_TO_UNDERLYING_H
39