35 lines
1.2 KiB
C
35 lines
1.2 KiB
C
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//===--- AlignOf.h - Portable calculation of type alignment -----*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines the AlignedCharArrayUnion class.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_SUPPORT_ALIGNOF_H
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#define LLVM_SUPPORT_ALIGNOF_H
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#include <type_traits>
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namespace llvm {
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/// A suitably aligned and sized character array member which can hold elements
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/// of any type.
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///
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/// This template is equivalent to std::aligned_union_t<1, ...>, but we cannot
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/// use it due to a bug in the MSVC x86 compiler:
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/// https://github.com/microsoft/STL/issues/1533
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/// Using `alignas` here works around the bug.
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template <typename T, typename... Ts> struct AlignedCharArrayUnion {
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using AlignedUnion = std::aligned_union_t<1, T, Ts...>;
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alignas(alignof(AlignedUnion)) char buffer[sizeof(AlignedUnion)];
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};
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} // end namespace llvm
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#endif // LLVM_SUPPORT_ALIGNOF_H
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