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
26template <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
34template <class _Tp>
35_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY constexpr underlying_type_t<_Tp>
36to_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