// { dg-do compile { target c++17 } }

// Copyright (C) 2020-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3.  If not see
// <http://www.gnu.org/licenses/>.

// { dg-error "must be a complete class" "" { target *-*-* } 0 }

#include <type_traits>

class X;

void test01()
{
  std::is_invocable<X, int>();		// { dg-error "required from here" }
  std::is_invocable<X>();		// { dg-error "required from here" }

  std::is_invocable_r<int, X, int>();		// { dg-error "required from here" }
  std::is_invocable_r<int, X>();		// { dg-error "required from here" }

  std::is_invocable_r<X, X()>();		// { dg-error "required from here" }
  std::is_invocable_r<X, X(int), int>();		// { dg-error "required from here" }
  std::is_invocable_r<X, X(int, int), int, int>();		// { dg-error "required from here" }

  std::is_invocable_r<X, X(), int, int>();		// { dg-error "required from here" }
}