1 // Copyright (C) 2015-2019 Free Software Foundation, Inc.
2 //
3 // This file is part of the GNU ISO C++ Library.  This library is free
4 // software; you can redistribute it and/or modify it under the
5 // terms of the GNU General Public License as published by the
6 // Free Software Foundation; either version 3, or (at your option)
7 // any later version.
8 
9 // This library is distributed in the hope that it will be useful,
10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 // GNU General Public License for more details.
13 
14 // You should have received a copy of the GNU General Public License along
15 // with this library; see the file COPYING3.  If not see
16 // <http://www.gnu.org/licenses/>.
17 
18 // { dg-options "-std=gnu++17" }
19 
20 #include <memory>
21 #include <testsuite_hooks.h>
22 
23 #if __cpp_lib_enable_shared_from_this < 201603
24 # error "__cpp_lib_enable_shared_from_this < 201603"
25 #endif
26 
27 struct X : public std::enable_shared_from_this<X> { };
28 
29 static_assert( noexcept(std::declval<X&>().weak_from_this()) );
30 static_assert( noexcept(std::declval<const X&>().weak_from_this()) );
31 
32 void
test01()33 test01()
34 {
35   std::shared_ptr<X> sp(new X);
36   auto wp1 = sp->weak_from_this();
37   std::weak_ptr<X> wp2 = sp;
38 
39   std::owner_less<> less;
40   VERIFY( !less(wp1, wp2) && !less(wp2, wp1) );
41   VERIFY( !less(wp1, wp2) && !less(wp2, wp1) );
42 }
43 
44 int
main()45 main()
46 {
47   test01();
48 }
49