pkg/front_end/testcases/general/typedef.dart

// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
// @dart=2.9
typedef _NullaryFunction();
typedef _UnaryFunction(args);
typedef _BinaryFunction(args, message);

main() {
  print(main is _NullaryFunction);
  print(main is _UnaryFunction);
  print(main is _BinaryFunction);
}