libstdc++-v3/testsuite/std/concepts/concepts.callable/invocable.cc

   1 // Copyright (C) 2019-2020 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::invocable<int> );
  24 static_assert( std::invocable<int()> );
  25 static_assert( std::invocable<int(*)()> );
  26 static_assert( std::invocable<int(&)()> );
  27 static_assert( ! std::invocable<int(), int> );
  28 static_assert( ! std::invocable<int() const> );
  29
  30 static_assert( std::invocable<int(const long*, short), long*, char> );
  31
  32 struct A;
  33 static_assert( std::invocable<int A::*, const A&> );
  34 static_assert( ! std::invocable<void (A::*)(long&), const A*, long&> );
  35 static_assert( std::invocable<void (A::*)(long&) const, A*, long&> );
  36
  37 struct F
  38 {
  39   void operator()() const;
  40   void operator()(int);
  41 };
  42 static_assert( std::invocable<F> );
  43 static_assert( std::invocable<F, int> );
  44 static_assert( std::invocable<const F&> );
  45 static_assert( ! std::invocable<const F&, int> );