| // 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 result of [NNBD_TOP_MERGE(Function?, Function?)] is |
| /// [Function?]. |
| /// |
| /// @author iarkh@unipro.ru |
| |
| // Requirements=nnbd-strong |
| |
| import "../../../Utils/expect.dart"; |
| |
| class B extends CHECK_TOP_MERGE<Function?> {} |
| class C extends CHECK_TOP_MERGE<Function?> {} |
| |
| class D extends B implements C {} |
| |
| main() { |
| Expect.isTrue(D().f is Function? Function(Function?)); |
| } |
