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()33test01() 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()45main() 46 { 47 test01(); 48 } 49