libstdc++-v3/testsuite/std/concepts/concepts.lang/concept.derived/1.cc

   1 // Copyright (C) 2019-2022 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 <concepts>
  22
  23 static_assert( !std::derived_from<int, int> );
  24 static_assert( !std::derived_from<int&, int> );
  25 static_assert( !std::derived_from<int, int&> );
  26 static_assert( !std::derived_from<int&&, int&> );
  27 static_assert( !std::derived_from<const int, int> );
  28 static_assert( !std::derived_from<const int, const int> );
  29
  30 struct A { };
  31 static_assert( std::derived_from<A, A> );
  32 static_assert( std::derived_from<A, const A> );
  33 static_assert( std::derived_from<A const, const A> );
  34 static_assert( std::derived_from<volatile A, const A> );
  35
  36 struct B : A { };
  37 static_assert( !std::derived_from<A, B> );
  38 static_assert( std::derived_from<B, A> );
  39 static_assert( std::derived_from<const B, A> );
  40 static_assert( std::derived_from<B, const A> );
  41 static_assert( std::derived_from<volatile B, const A> );
  42
  43 struct C : private A { };
  44 static_assert( !std::derived_from<A, C> );
  45 static_assert( !std::derived_from<C, A> );
  46
  47 struct D : A { };
  48 struct E : B, D { };
  49 static_assert( !std::derived_from<A, E> );
  50 static_assert( !std::derived_from<E, A> );