libstdc++-v3/testsuite/23_containers/unordered_set/92124.cc

   1 // Copyright (C) 2020-2025 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 run { target c++11 } }
  19
  20 #include <unordered_set>
  21
  22 #include <testsuite_allocator.h>
  23 #include <testsuite_hooks.h>
  24
  25 int moves = 0;
  26
  27 struct X
  28 {
  29   X() = default;
  30   X(const X&) = default;
  31   X(int i) : _i(i) {}
  32
  33   // Move constructor might throw
  34   X(X&& x) noexcept(false)
  35   {
  36     this->_i = x._i;
  37     x._i = -1;
  38     ++moves;
  39   }
  40
  41   int _i;
  42 };
  43
  44 struct XHasher
  45 {
  46   std::size_t
  47   operator()(const X& x) const noexcept
  48   { return x._i; }
  49 };
  50
  51 struct XEqualTo
  52 {
  53   bool
  54   operator()(const X& lhs, const X& rhs) const noexcept
  55   { return lhs._i == rhs._i; }
  56 };
  57
  58 void
  59 test01()
  60 {
  61   using A = __gnu_test::propagating_allocator<X, false>;
  62   A a1(1), a2(2);
  63   std::unordered_set<X, XHasher, XEqualTo, A> u1(a1), u2(a2);
  64   u1 = { X(0), X(1), X(2) };
  65   u2 = { X(3), X(4), X(5) };
  66
  67   moves = 0;
  68   u1 = std::move(u2);
  69
  70   VERIFY( moves == 3 );
  71   VERIFY( u1.count(X(1)) == 0 );
  72   VERIFY( u1.count(X(3)) == 1 );
  73 }
  74
  75 int
  76 main()
  77 {
  78   test01();
  79 }