llvm-project/libcxx/include/__utility/to_underlying.h

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// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___UTILITY_TO_UNDERLYING_H
#define _LIBCPP___UTILITY_TO_UNDERLYING_H
#include <__config>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#ifndef _LIBCPP_CXX03_LANG
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY constexpr typename underlying_type<_Tp>::type
__to_underlying(_Tp __val) noexcept {
return static_cast<typename underlying_type<_Tp>::type>(__val);
}
#endif // !_LIBCPP_CXX03_LANG
#if _LIBCPP_STD_VER > 20
template <class _Tp>
_LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY constexpr underlying_type_t<_Tp>
to_underlying(_Tp __val) noexcept {
return _VSTD::__to_underlying(__val);
}
#endif
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___UTILITY_TO_UNDERLYING_H