1 // Copyright (C) 2012-2021 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-do compile { target c++11 } }
19 
20 // libstdc++/52591
21 
22 #include <vector>
23 #include <memory>
24 #include <type_traits>
25 
26 // Move-assignment of std::vector<T> is allowed for non-MoveAssignable T when
27 // the allocator type propagates. As an extension we also allow it if the
28 // allocator type is known to always compare equal.
29 
30 struct C
31 {
32     C& operator=(C&&) = delete;
33 };
34 
test01()35 void test01()
36 {
37     std::vector<C> a;
38     a = std::vector<C>();
39 }
40 
41 template<typename T>
42 struct A1 : std::allocator<T>
43 {
44   template<typename U> struct rebind { typedef A1<U> other; };
45 
46   A1() = default;
A1A147   template<typename U> A1(const A1<U>&) { }
48 
49   using propagate_on_container_move_assignment = std::true_type;
50   using is_always_equal = std::false_type;
51 };
52 
test02()53 void test02()
54 {
55   using test_type = std::vector<C, A1<C>>;
56   static_assert(std::is_nothrow_move_assignable<test_type>::value,
57       "vector is nothrow move-assignable if allocator propagates");
58 }
59 
60 template<typename T>
61 struct A2 : std::allocator<T>
62 {
63   template<typename U> struct rebind { typedef A1<U> other; };
64 
65   A2() = default;
A2A266   template<typename U> A2(const A2<U>&) { }
67 
68   using propagate_on_container_move_assignment = std::false_type;
69   using is_always_equal = std::true_type;
70 };
71 
test03()72 void test03()
73 {
74   using test_type = std::vector<C, A2<C>>;
75   static_assert(std::is_nothrow_move_assignable<test_type>::value,
76       "vector is nothrow move-assignable if allocator is always equal");
77 }
78