1 // { dg-do compile { target c++11 } }
2 // { dg-additional-options "-pthread" { target pthread } }
3
4 // Copyright (C) 2014-2021 Free Software Foundation, Inc.
5 //
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 3, or (at your option)
10 // any later version.
11
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
16
17 // You should have received a copy of the GNU General Public License along
18 // with this library; see the file COPYING3. If not see
19 // <http://www.gnu.org/licenses/>.
20
21 // libstdc++/60497
22
23 #include <mutex>
24 #include <memory>
25 #include <functional>
26
27 struct A;
28 template<typename T> struct B { T t; };
29
30 using UP = std::unique_ptr<B<A>>;
31
f(UP &)32 void f(UP&) { }
33
g(UP & p)34 void g(UP& p)
35 {
36 std::once_flag o;
37 std::call_once(o, f, std::ref(p));
38 }
39