libstdc++-v3/testsuite/23_containers/vector/cons/87809.cc

   1 // Copyright (C) 2018-2025 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 #include <vector>
  21
  22 template <typename T>
  23 struct Alloc
  24 {
  25   using value_type = T;
  26
  27   T* allocate(unsigned n);
  28   void deallocate(T* p, unsigned n);
  29
  30   Alloc(int) { }
  31
  32   template<typename U>
  33     Alloc(const Alloc<U>&) { }
  34 };
  35
  36 template<typename T, typename U>
  37   bool operator==(Alloc<T>, Alloc<U>) { return true; }
  38 template<typename T, typename U>
  39   bool operator!=(Alloc<T>, Alloc<U>) { return false; }
  40
  41 constexpr bool b
  42   = std::is_default_constructible<std::vector<int, Alloc<int>>>::value;