| // Copyright (c) 2020, 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: |
| /// Left Null: if T0 is Null then: |
| /// - if T1 is a type variable (promoted or not) the query is false |
| /// - If T1 is FutureOr<S> for some S, then the query is true iff Null <: S. |
| /// - If T1 is Null, S? or S* for some S, then the query is true. |
| /// - Otherwise, the query is false |
| /// @description Check that if type T0 is Null and T1 is a type variable then T0 |
| /// is not subtype of a type T1. |
| /// @author sgrekhov@unipro.ru |
| |
| class C {} |
| class T1 extends C {} |
| |
| T test<T extends C?>(T t, Null n) { |
| t = n; |
| // ^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| foo<T>(n); |
| // ^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| return n; |
| // ^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| } |
| |
| foo<T>(T t) {} |
| |
| main() { |
| test<T1>(new T1(), null); |
| } |