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

   1 // Copyright (C) 2019-2021 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::assignable_from<void, void> );
  24 static_assert( !std::assignable_from<void*, int*> );
  25 static_assert( std::assignable_from<void*&, int*> );
  26 static_assert( !std::assignable_from<void*&, const int*> );
  27 static_assert( std::assignable_from<const void*&, const int*> );
  28 static_assert( !std::assignable_from<char, char> );
  29 static_assert( std::assignable_from<char&, char> );
  30 static_assert( !std::assignable_from<float, float> );
  31 static_assert( std::assignable_from<float&, double> );
  32 static_assert( std::assignable_from<int*&, int*> );
  33 static_assert( std::assignable_from<int&, int&> );
  34 static_assert( std::assignable_from<int&, int&&> );
  35 static_assert( !std::assignable_from<int&&, int> );
  36 static_assert( !std::assignable_from<const int&, int> );
  37 static_assert( !std::assignable_from<const int&, int&> );
  38 static_assert( !std::assignable_from<const int&, const int> );
  39 static_assert( !std::assignable_from<const int&, const int&> );
  40 static_assert( !std::assignable_from<int(&)[], int(&)[]> );
  41 static_assert( !std::assignable_from<int(&)[], int> );
  42 static_assert( !std::assignable_from<int(&)[2], int(&)[2]> );
  43 static_assert( !std::assignable_from<int(), int()> );
  44 static_assert( !std::assignable_from<int(*)(), int(*)()> );
  45 static_assert( std::assignable_from<int(*&)(), int(*)()> );
  46 static_assert( std::assignable_from<int(*&)(), std::nullptr_t> );
  47 static_assert( std::assignable_from<int(*&)(), int(*)() noexcept> );
  48 static_assert( std::assignable_from<int(*&)(), int(&)() noexcept> );
  49 static_assert( !std::assignable_from<int(&)(), std::nullptr_t> );
  50 static_assert( !std::assignable_from<int(&)(), int(&)() noexcept> );
  51
  52 enum E { };
  53 static_assert( !std::assignable_from<E, E> );
  54 static_assert( std::assignable_from<E&, E> );
  55 static_assert( std::assignable_from<E&, E&> );
  56 static_assert( std::assignable_from<E&, const E&> );
  57 static_assert( !std::assignable_from<const E&, const E&> );
  58 enum class CE { };
  59 static_assert( !std::assignable_from<CE, CE> );
  60 static_assert( std::assignable_from<CE&, CE&> );
  61 static_assert( std::assignable_from<CE&, const CE&> );
  62 static_assert( !std::assignable_from<const CE&, const CE&> );
  63 struct A { };
  64 static_assert( !std::assignable_from<A, A> );
  65 static_assert( std::assignable_from<A&, A> );
  66 static_assert( !std::assignable_from<A, A&> );
  67 static_assert( std::assignable_from<A&, const A&> );
  68 union B { };
  69 static_assert( !std::assignable_from<B, B> );
  70 static_assert( std::assignable_from<B&, B> );
  71 static_assert( !std::assignable_from<B, B&> );
  72 static_assert( std::assignable_from<B&, const B&> );
  73
  74 struct C
  75 {
  76   C(int) { }
  77   C& operator=(const C&) { return *this; }
  78   C& operator=(int) { return *this; }
  79   void operator=(void*) { }
  80 };
  81 static_assert( std::assignable_from<C&, C> );
  82 static_assert( std::assignable_from<C&, const C&> );
  83 static_assert( std::assignable_from<C&, int> );
  84 static_assert( !std::assignable_from<C&, void*> );
  85 static_assert( !std::assignable_from<C&, std::nullptr_t> );