| // Copyright (c) 2016, 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 Evaluation of a compound assignment of the form C.v ??= e, |
| /// where C is a type literal, is equivalent to the evaluation of the expression |
| /// ((x) => x == null? C.v = e : x)(C.v) where x is a fresh variable that is not |
| /// used in e. |
| /// @description Checks that in expression of the form C.v ??= e value is set only |
| /// if C.v == null |
| /// @author sgrekhov@unipro.ru |
| |
| |
| import '../../../../Utils/expect.dart'; |
| |
| class C { |
| static var v = null; |
| } |
| |
| main() { |
| C.v = null; |
| C.v ??= 1; |
| Expect.equals(1, C.v); |
| |
| C.v ??= 2; |
| Expect.equals(1, C.v); |
| } |