| // @dart = 2.9 | |
| library test; | |
| import 'dart:async'; | |
| T f<T>() => null; | |
| class B<T> { | |
| D<T> operator [](E<T> x) => null; | |
| } | |
| class C<U> extends B<Future<U>> { | |
| E<Future<U>> operator [](Object x) => null; | |
| void h() {} | |
| } | |
| class D<T> {} | |
| class E<T> extends D<T> {} | |
| main() {} |