| // 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 If a class [C] in an opted-in library implements the same generic |
| /// class [I] more than once as [I0], .., [In], and at least one of the [Ii] is |
| /// not syntactically equal to the others, then it is an error if |
| /// [NNBD_TOP_MERGE(S0, ..., Sn)] is not defined where [Si] is [NORM(Ii)]. |
| /// Otherwise, for the purposes of runtime subtyping checks, [C] is considered to |
| /// implement the canonical interface given by [NNBD_TOP_MERGE(S0, ..., Sn)]. |
| /// |
| /// @description Check that error occurs as a result of [NNBD_TOP_MERGE( |
| /// FutureOr<int>, FutureOr<int?>]. |
| /// |
| /// @author iarkh@unipro.ru |
| |
| |
| import "dart:async"; |
| |
| class A<T> {} |
| class B implements A<FutureOr<int >> {} |
| class C implements A<FutureOr<int?>> {} |
| |
| class D extends B implements C {} |
| // ^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| |
| class E extends C implements B {} |
| // ^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| |
| void main() {} |
