libstdc++-v3/testsuite/23_containers/deque/allocator/move_assign-2.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 // { dg-options "-fno-access-control" }
  20
  21 // libstdc++/52591
  22
  23 #include <deque>
  24 #include <memory>
  25 #include <type_traits>
  26
  27
  28 // Move-assignment of std::deque<T> is allowed for non-MoveAssignable T when
  29 // the allocator type propagates. As an extension we also allow it if the
  30 // allocator type is known to always compare equal.
  31
  32 struct C
  33 {
  34     C& operator=(C&&) = delete;
  35 };
  36
  37 template<typename T>
  38 struct A1 : std::allocator<T>
  39 {
  40   template<typename U> struct rebind { typedef A1<U> other; };
  41
  42   A1() = default;
  43   template<typename U> A1(const A1<U>&) { }
  44
  45   using propagate_on_container_move_assignment = std::true_type;
  46   using is_always_equal = std::false_type;
  47 };
  48
  49 void test01()
  50 {
  51   using test_type = std::deque<C, A1<C>>;
  52   static_assert(std::is_move_assignable<test_type>::value,
  53       "deque is move-assignable if allocator propagates");
  54 }
  55
  56 template<typename T>
  57 struct A2 : std::allocator<T>
  58 {
  59   template<typename U> struct rebind { typedef A2<U> other; };
  60
  61   A2() = default;
  62   template<typename U> A2(const A2<U>&) { }
  63
  64   using propagate_on_container_move_assignment = std::false_type;
  65
  66   using is_always_equal = std::true_type;
  67 };
  68
  69 void test02()
  70 {
  71   using test_type = std::deque<C, A2<C>>;
  72   static_assert(std::is_nothrow_move_assignable<test_type>::value,
  73       "deque is nothrow move-assignable if allocator is always equal");
  74 }