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 // <mutex>
11 
12 // struct once_flag;
13 
14 // constexpr once_flag() noexcept;
15 
16 #include <mutex>
17 #include "test_macros.h"
18 
19 int main()
20 {
21     {
22     std::once_flag f;
23     }
24 #if TEST_STD_VER >= 11
25     {
26     constexpr std::once_flag f;
27     }
28 #endif
29 }
30