| //===--- AlignOf.h - Portable calculation of type alignment -----*- 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines the AlignedCharArrayUnion class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_SUPPORT_ALIGNOF_H |
| #define LLVM_SUPPORT_ALIGNOF_H |
| |
| #include <type_traits> |
| |
| namespace llvm { |
| |
| /// A suitably aligned and sized character array member which can hold elements |
| /// of any type. |
| /// |
| /// This template is equivalent to std::aligned_union_t<1, ...>, but we cannot |
| /// use it due to a bug in the MSVC x86 compiler: |
| /// https://github.com/microsoft/STL/issues/1533 |
| /// Using `alignas` here works around the bug. |
| template <typename T, typename... Ts> struct AlignedCharArrayUnion { |
| using AlignedUnion = std::aligned_union_t<1, T, Ts...>; |
| alignas(alignof(AlignedUnion)) char buffer[sizeof(AlignedUnion)]; |
| }; |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_SUPPORT_ALIGNOF_H |
