LLVM  10.0.0svn
AlignOf.h
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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 "llvm/Support/Compiler.h"
17 #include <cstddef>
18 
19 namespace llvm {
20 
21 namespace detail {
22 
23 template <typename T, typename... Ts> class AlignerImpl {
24  T t;
25  AlignerImpl<Ts...> rest;
26  AlignerImpl() = delete;
27 };
28 
29 template <typename T> class AlignerImpl<T> {
30  T t;
31  AlignerImpl() = delete;
32 };
33 
34 template <typename T, typename... Ts> union SizerImpl {
35  char arr[sizeof(T)];
36  SizerImpl<Ts...> rest;
37 };
38 
39 template <typename T> union SizerImpl<T> { char arr[sizeof(T)]; };
40 } // end namespace detail
41 
42 /// A suitably aligned and sized character array member which can hold elements
43 /// of any type.
44 ///
45 /// These types may be arrays, structs, or any other types. This exposes a
46 /// `buffer` member which can be used as suitable storage for a placement new of
47 /// any of these types.
48 template <typename T, typename... Ts> struct AlignedCharArrayUnion {
49  alignas(::llvm::detail::AlignerImpl<T, Ts...>) char buffer[sizeof(
51 };
52 
53 } // end namespace llvm
54 
55 #endif // LLVM_SUPPORT_ALIGNOF_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
SizerImpl< Ts... > rest
Definition: AlignOf.h:36
A suitably aligned and sized character array member which can hold elements of any type...
Definition: AlignOf.h:48