// Copyright (c) 2021, 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.

/**
 * @assertion We say that a type T is nullable if Null <: T and not T <: Object.
 * This is equivalent to the syntactic criterion that T is any of:
 *  Null
 *  S? for some S
 *  S* for some S where S is nullable
 *  FutureOr<S> for some S where S is nullable
 *  dynamic
 *  void
 *
 * @description Check that null can be assigned to nullable type. Test S? for
 * some S. Test type aliases
 * @author sgrekhov@unipro.ru
 */
// SharedOptions=--enable-experiment=nonfunction-type-aliases
// Requirements=nnbd-weak
class C {}

typedef CAlias = C?;
typedef IntAlias = int?;
typedef StringAlias = String?;

main() {
  CAlias c = C();
  c = null;

  IntAlias i = null;

  StringAlias s = "";
  s = null;
}