//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <mutex>
// struct once_flag;
// once_flag(const once_flag&) = delete;
#include <mutex>
int main()
{
std::once_flag f;
std::once_flag f2(f);
}