| // 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 of selectors is extended to allow null-aware |
| /// subscripting using the syntax e1?[e2] which evaluates to null if e1 |
| /// evaluates to null and otherwise evaluates as e1[e2]. |
| /// |
| /// @description Check that the grammar of selectors is extended to allow |
| /// null-aware subscripting using the syntax e1?[e2] which evaluates to null if |
| /// e1 evaluates to null and otherwise evaluates as e1[e2]. Test type aliases |
| /// @author sgrekhov@unipro.ru |
| |
| // Requirements=nnbd-strong |
| import '../../Utils/expect.dart'; |
| |
| class C { |
| int operator[](int index) => index * 2; |
| } |
| |
| typedef CAlias = C?; |
| |
| CAlias c = null; |
| CAlias c1 = C(); |
| |
| main() { |
| Expect.isNull(c?[42]); |
| Expect.equals(4, c1?[2]); |
| } |