| // 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 We say that a type T0 is a subtype of a type T1 (written T0 <: T1) |
| /// when: |
| /// Right Object: if T1 is Object then: |
| /// - if T0 is an unpromoted type variable with bound B then T0 <: T1 iff |
| /// B <: Object |
| /// - if T0 is a promoted type variable X & S then T0 <: T1 iff S <: Object |
| /// - if T0 is FutureOr<S> for some S, then T0 <: T1 iff S <: Object. |
| /// - if T0 is S* for any S, then T0 <: T1 iff S <: T1 |
| /// - if T0 is Null, dynamic, void, or S? for any S, then the subtyping does not |
| /// hold (per above, the result of the subtyping query is false). |
| /// - Otherwise T0 <: T1 is true. |
| /// @description Check that if T0 is FutureOr<S> for some S but S is not subtype |
| /// of Object then T0 is not subtype of T1 |
| /// @author sgrekhov@unipro.ru |
| |
| import "dart:async"; |
| |
| class S {} |
| |
| FutureOr<S?> t0Instance = new Future.value(new S()); |
| Object t1Instance = new Object(); |
| |
| const t1Default = const Object(); |
| |
| //# @T0 = FutureOr<S?> |
| //# @T1 = Object |
