| // 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 With sound null safety, all generic const constructors and |
| /// generic const literals are evaluated using the actual type arguments |
| /// provided, whether legacy or non-legacy. This ensures that with sound null |
| /// safety, the final consistent semantics are obeyed. |
| /// |
| /// @description Checks dynamically that actual generic class type parameter is |
| /// evaluated correctly for [int?] type argument in weak mode. |
| /// |
| /// This is a known issue with the common front end: It uses `LEGACY_ERASURE` on |
| /// type arguments to collection literals and `<constObjectExpression>`, and this |
| /// eliminates `?` from types (not just top-level, also `List<Object?>` --> |
| /// `List<Object*>*`). The front end will change to use a different rule, which |
| /// is currently being debated in |
| /// https://github.com/dart-lang/language/issues/1346. |
| /// |
| /// In any case, seems like it's highly unlikely that the rules in the end will |
| /// erase `?` and make `<Object?>[]` and `<Object>[]` canonicalize to the same |
| /// object (and this would hold both when the latter occurs in legacy code and |
| /// when it occurs in code with null safety). |
| /// |
| /// So issue #39678 with the common front end has been reported here. |
| /// @Issue 39678,44503 |
| /// @author iarkh@unipro.ru |
| |
| // Requirements=nnbd-weak |
| |
| import "../../../Utils/expect.dart"; |
| |
| class A<T> { |
| const A(); |
| void testme() { Expect.equals(typeOf<int?>(), T); } |
| } |
| |
| main() { |
| const a = A<int?>(); |
| a.testme(); |
| } |