libstdc++-v3/testsuite/24_iterators/reverse_iterator/dr3435.cc

   1 // Copyright (C) 2020-2022 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-options "-std=gnu++2a" }
  19 // { dg-do compile { target c++2a } }
  20
  21 #include <iterator>
  22 #include <compare>
  23
  24 // LWG 3435.
  25 // three_way_comparable_with<reverse_iterator<int*>, reverse_iterator<const int*>>
  26
  27 using RI = std::reverse_iterator<int*>;
  28 using CRI = std::reverse_iterator<const int*>;
  29
  30 static_assert( std::three_way_comparable_with<RI, CRI> );
  31
  32 static_assert( std::is_convertible_v<const RI&, CRI> );
  33 static_assert( ! std::is_convertible_v<const CRI&, RI> );
  34
  35 static_assert( std::is_assignable_v<CRI, const RI&> );
  36 static_assert( ! std::is_assignable_v<RI, const CRI&> );