| // 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 Currently you can do instantiated tear-offs of instance methods. |
| /// We restrict that to interface methods, which precisely excludes the call |
| /// methods of function types. We do not allow instantiating function values, |
| /// and therefore also cannot allow side-stepping that restriction by |
| /// instantiation the .call "instance" method of such a value. |
| /// |
| /// That makes it a compile-time error to explicitly instantiate the call method |
| /// of an expression with a function type or of type Function, and the tear-off |
| /// of a call method of a function type is not subject to implicit instantiation |
| /// (so the tear-off is always generic, even if the context type requires it not |
| /// to be, which is then guaranteed to introduce a type error). |
| /// |
| /// @description Checks that it is no compile-time error to tear-off a call |
| /// method for int Function<int>(int) f = funcValue.call; case. |
| /// @author sgrekhov@unipro.ru |
| |
| // SharedOptions=--enable-experiment=constructor-tearoffs |
| |
| import "../../Utils/expect.dart"; |
| |
| main() { |
| T foo<T>(T value) => value; |
| var funcValue = foo; |
| X Function<X>(X) f = funcValue.call; |
| Expect.equals(42, f(42)); |
| Expect.equals(3.14, f<double>(3.14)); |
| } |