libcxx/include/__cxx03/__bit/bit_cast.h

// -*- 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___BIT_BIT_CAST_H
#define _LIBCPP___BIT_BIT_CAST_H

#include <__config>
#include <__type_traits/is_trivially_copyable.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

#ifndef _LIBCPP_CXX03_LANG

template <class _ToType, class _FromType>
_LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI constexpr _ToType __bit_cast(const _FromType& __from) noexcept {
  return __builtin_bit_cast(_ToType, __from);
}

#endif // _LIBCPP_CXX03_LANG

#if _LIBCPP_STD_VER >= 20

template <class _ToType, class _FromType>
  requires(sizeof(_ToType) == sizeof(_FromType) && is_trivially_copyable_v<_ToType> &&
           is_trivially_copyable_v<_FromType>)
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _ToType bit_cast(const _FromType& __from) noexcept {
  return __builtin_bit_cast(_ToType, __from);
}

#endif // _LIBCPP_STD_VER >= 20

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___BIT_BIT_CAST_H