libcxx/include/__bit/bit_cast.h

   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___BIT_BIT_CAST_H
  11 #define _LIBCPP___BIT_BIT_CAST_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_BEGIN_NAMESPACE_STD
  21
  22 #if _LIBCPP_STD_VER > 17
  23
  24 template<class _ToType, class _FromType, class = enable_if_t<
  25   sizeof(_ToType) == sizeof(_FromType) &&
  26   is_trivially_copyable_v<_ToType> &&
  27   is_trivially_copyable_v<_FromType>
  28 >>
  29 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI
  30 constexpr _ToType bit_cast(_FromType const& __from) noexcept {
  31     return __builtin_bit_cast(_ToType, __from);
  32 }
  33
  34 #endif // _LIBCPP_STD_VER > 17
  35
  36 _LIBCPP_END_NAMESPACE_STD
  37
  38 #endif // _LIBCPP___BIT_BIT_CAST_H