| // Copyright (c) 2021, 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 will introduce syntax allowing you to explicitly instantiate a |
| /// function tear-off and a type literal for a generic class. The former for |
| /// consistency with constructor tear-offs, the latter to introduce in-line |
| /// types without needing a typedef, like we did for function types. And we do |
| /// both now because they share the same grammar productions. |
| /// |
| /// Example: |
| /// |
| /// T id<T>(T value) => value; |
| /// var idInt = id<int>; // Explicitly instantiated tear-off, saves on writing function types. |
| /// and |
| /// Type intList = List<int>; // In-line instantiated type literal. |
| /// |
| /// @description Checks example from the Spec. |
| /// @author sgrekhov@unipro.ru |
| |
| // SharedOptions=--enable-experiment=constructor-tearoffs |
| |
| import "../../Utils/expect.dart"; |
| |
| T id<T>(T value) => value; |
| var idInt = id<int>; |
| |
| main() { |
| dynamic v = 42; |
| var i = idInt(v); |
| Expect.isTrue(i is int); |
| Expect.isFalse(i is String); // to check that i is not dynamic |
| Expect.runtimeIsType<int>(i); |
| Expect.runtimeIsNotType<String>(i); |
| } |