| //===--- 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 "llvm/Support/Compiler.h" |
| #include <cstddef> |
| |
| namespace llvm { |
| |
| namespace detail { |
| |
| template <typename T, typename... Ts> class AlignerImpl { |
| T t; |
| AlignerImpl<Ts...> rest; |
| AlignerImpl() = delete; |
| }; |
| |
| template <typename T> class AlignerImpl<T> { |
| T t; |
| AlignerImpl() = delete; |
| }; |
| |
| template <typename T, typename... Ts> union SizerImpl { |
| char arr[sizeof(T)]; |
| SizerImpl<Ts...> rest; |
| }; |
| |
| template <typename T> union SizerImpl<T> { char arr[sizeof(T)]; }; |
| } // end namespace detail |
| |
| /// A suitably aligned and sized character array member which can hold elements |
| /// of any type. |
| /// |
| /// These types may be arrays, structs, or any other types. This exposes a |
| /// `buffer` member which can be used as suitable storage for a placement new of |
| /// any of these types. |
| template <typename T, typename... Ts> struct AlignedCharArrayUnion { |
| alignas(::llvm::detail::AlignerImpl<T, Ts...>) char buffer[sizeof( |
| llvm::detail::SizerImpl<T, Ts...>)]; |
| }; |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_SUPPORT_ALIGNOF_H |