libstdc++-v3/testsuite/23_containers/vector/52591.cc

   1 // Copyright (C) 2012-2025 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
  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;
  47   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
  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 A2<U> other; };
  64
  65   A2() = default;
  66   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
  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 }