| // Copyright (c) 2019, 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 The grammar for types does not allow multiple successive ? |
| /// operators on a type. That is, the grammar for types is nominally equivalent |
| /// to: |
| /// type' ::= functionType |
| /// | qualified typeArguments? |
| /// type ::= type' `?`? |
| /// |
| /// @description Check that it is no error to have multiple ? but not in the type |
| /// declaration. Test type aliases |
| /// @author sgrekhov@unipro.ru |
| |
| // Requirements=nnbd-strong |
| class A {} |
| |
| typedef AAlias1 = A?; |
| typedef AAlias2 = AAlias1?; |
| |
| main() { |
| AAlias1 a1 = null; |
| AAlias2 a2 = null; |
| } |
