1 //===----------------------------------------------------------------------===//
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 // UNSUPPORTED: c++03, c++11, c++14
10 
11 // <any>
12 
13 // Check that the size and alignment of any are what we expect.
14 
15 #include <any>
16 #include "test_macros.h"
17 #include "any_helpers.h"
18 
19 constexpr std::size_t BufferSize = (sizeof(void*) * 3);
20 constexpr std::size_t BufferAlignment = alignof(void*);
21 // Clang doesn't like "alignof(BufferAlignment * 2)" due to PR13986.
22 // So we create "DoubleBufferAlignment" instead.
23 constexpr std::size_t DoubleBufferAlignment = BufferAlignment * 2;
24 
25 class SmallThrowsDtor
26 {
27 public:
SmallThrowsDtor()28     SmallThrowsDtor() {}
SmallThrowsDtor(SmallThrowsDtor const &)29     SmallThrowsDtor(SmallThrowsDtor const &) noexcept {}
SmallThrowsDtor(SmallThrowsDtor &&)30     SmallThrowsDtor(SmallThrowsDtor &&) noexcept {}
~SmallThrowsDtor()31     ~SmallThrowsDtor() noexcept(false) {}
32 };
33 
34 
35 struct alignas(1) MaxSizeType {
36     char buff[BufferSize];
37 };
38 
39 struct alignas(BufferAlignment) MaxAlignType {
40 };
41 
42 struct alignas(BufferAlignment) MaxSizeAndAlignType {
43     char buff[BufferSize];
44 };
45 
46 
47 struct alignas(1) OverSizeType {
48     char buff[BufferSize + 1];
49 };
50 
51 struct alignas(DoubleBufferAlignment) OverAlignedType {
52 };
53 
54 struct alignas(DoubleBufferAlignment) OverSizeAndAlignedType {
55     char buff[BufferSize + 1];
56 };
57 
main(int,char **)58 int main(int, char**)
59 {
60     using std::any;
61     using std::__any_imp::_IsSmallObject;
62     static_assert(_IsSmallObject<small>::value, "");
63     static_assert(_IsSmallObject<void*>::value, "");
64     static_assert(!_IsSmallObject<SmallThrowsDtor>::value, "");
65     static_assert(!_IsSmallObject<large>::value, "");
66     {
67         // Check a type that meets the size requirement *exactly* and has
68         // a lesser alignment requirement is considered small.
69         typedef MaxSizeType T;
70         static_assert(sizeof(T) == BufferSize, "");
71         static_assert(alignof(T) < BufferAlignment,   "");
72         static_assert(_IsSmallObject<T>::value, "");
73     }
74     {
75         // Check a type that meets the alignment requirement *exactly* and has
76         // a lesser size is considered small.
77         typedef MaxAlignType T;
78         static_assert(sizeof(T) < BufferSize, "");
79         static_assert(alignof(T) == BufferAlignment,   "");
80         static_assert(_IsSmallObject<T>::value, "");
81     }
82     {
83         // Check a type that meets the size and alignment requirements *exactly*
84         // is considered small.
85         typedef MaxSizeAndAlignType T;
86         static_assert(sizeof(T) == BufferSize, "");
87         static_assert(alignof(T) == BufferAlignment,   "");
88         static_assert(_IsSmallObject<T>::value, "");
89     }
90     {
91         // Check a type that meets the alignment requirements but is over-sized
92         // is not considered small.
93         typedef OverSizeType T;
94         static_assert(sizeof(T) > BufferSize, "");
95         static_assert(alignof(T) < BufferAlignment, "");
96         static_assert(!_IsSmallObject<T>::value, "");
97     }
98     {
99         // Check a type that meets the size requirements but is over-aligned
100         // is not considered small.
101         typedef OverAlignedType T;
102         static_assert(sizeof(T) < BufferSize, "");
103         static_assert(alignof(T) > BufferAlignment, "");
104         static_assert(!_IsSmallObject<T>::value, "");
105     }
106     {
107         // Check a type that exceeds both the size an alignment requirements
108         // is not considered small.
109         typedef OverSizeAndAlignedType T;
110         static_assert(sizeof(T) > BufferSize, "");
111         static_assert(alignof(T) > BufferAlignment, "");
112         static_assert(!_IsSmallObject<T>::value, "");
113     }
114 
115   return 0;
116 }
117