1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // UNSUPPORTED: libcpp-has-no-threads
11 
12 // <atomic>
13 
14 // struct atomic_flag
15 
16 // atomic_flag() = default;
17 
18 #include <atomic>
19 #include <new>
20 #include <cassert>
21 
main()22 int main()
23 {
24     std::atomic_flag f;
25     f.clear();
26     assert(f.test_and_set() == 0);
27     {
28         typedef std::atomic_flag A;
29         _ALIGNAS_TYPE(A) char storage[sizeof(A)] = {1};
30         A& zero = *new (storage) A();
31         assert(!zero.test_and_set());
32         zero.~A();
33     }
34 }
35