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

   1 // Copyright (C) 2019-2024 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++20 } }
  19
  20 #include <concepts>
  21
  22 static_assert( std::common_with<int, int> );
  23 static_assert( std::common_with<int, const int> );
  24 static_assert( std::common_with<int&&, const int&> );
  25 static_assert( std::common_with<int&, const int&&> );
  26 static_assert( std::common_with<void, void> );
  27 static_assert( ! std::common_with<int, void> );
  28 static_assert( ! std::common_with<int, int*> );
  29 static_assert( ! std::common_with<int, int()> );
  30
  31 static_assert( std::common_with<int, short> );
  32 static_assert( std::common_with<short, int> );
  33 static_assert( std::common_with<void*, const int*> );
  34
  35 struct A { A(int) { } };
  36 static_assert( std::common_with<A, int> );
  37
  38 struct B { };
  39 static_assert( ! std::common_with<A, B> );
  40
  41 struct C { C(const A&) { } };
  42 static_assert( std::common_with<A, C> );
  43 static_assert( std::common_with<A, const C> );
  44 static_assert( std::common_with<const A, C> );
  45 static_assert( std::common_with<const A, const C> );
  46
  47 struct D;
  48 struct E { E(const D&) { } };
  49 struct D { D(const E&) { } };
  50 static_assert( ! std::common_with<D, E> ); // ambiguous conversion
  51
  52 struct F { };
  53 struct G { };
  54 struct H {
  55   H(const F&) { }
  56   H(const G&) { }
  57 };
  58 namespace std
  59 {
  60   template<> struct common_type<F, G> { using type = H; };
  61   template<> struct common_type<G, F> { using type = H; };
  62 }
  63
  64 static_assert( std::common_with<F, G> );
  65 static_assert( std::common_with<F, const G> );
  66 static_assert( std::common_with<const F, G> );
  67 static_assert( std::common_with<const F, const G> );
  68
  69 struct Base { };
  70 struct Derived : Base { };
  71 static_assert( std::common_with<Derived, Base> );
  72 static_assert( std::common_with<Derived*, Base*> );