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| Rev | Author | Line No. | Line | 
|---|---|---|---|
| 14 | pmbaty | 1 | //===--- AlignOf.h - Portable calculation of type alignment -----*- C++ -*-===// | 
| 2 | // | ||
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | ||
| 4 | // See https://llvm.org/LICENSE.txt for license information. | ||
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | ||
| 6 | // | ||
| 7 | //===----------------------------------------------------------------------===// | ||
| 8 | // | ||
| 9 | // This file defines the AlignedCharArrayUnion class. | ||
| 10 | // | ||
| 11 | //===----------------------------------------------------------------------===// | ||
| 12 | |||
| 13 | #ifndef LLVM_SUPPORT_ALIGNOF_H | ||
| 14 | #define LLVM_SUPPORT_ALIGNOF_H | ||
| 15 | |||
| 16 | #include <type_traits> | ||
| 17 | |||
| 18 | namespace llvm { | ||
| 19 | |||
| 20 | /// A suitably aligned and sized character array member which can hold elements | ||
| 21 | /// of any type. | ||
| 22 | /// | ||
| 23 | /// This template is equivalent to std::aligned_union_t<1, ...>, but we cannot | ||
| 24 | /// use it due to a bug in the MSVC x86 compiler: | ||
| 25 | /// https://github.com/microsoft/STL/issues/1533 | ||
| 26 | /// Using `alignas` here works around the bug. | ||
| 27 | template <typename T, typename... Ts> struct AlignedCharArrayUnion { | ||
| 28 | using AlignedUnion = std::aligned_union_t<1, T, Ts...>; | ||
| 29 | alignas(alignof(AlignedUnion)) char buffer[sizeof(AlignedUnion)]; | ||
| 30 | }; | ||
| 31 | |||
| 32 | } // end namespace llvm | ||
| 33 | |||
| 34 | #endif // LLVM_SUPPORT_ALIGNOF_H |