| /* |
| * 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 Let f be an asynchronous non-generator function with declared |
| * return type T. Then the future value type of f is futureValueType(T). The |
| * function futureValueType is defined as follows: |
| * |
| * futureValueType(S?) = futureValueType(S), for all S. |
| * futureValueType(S*) = futureValueType(S), for all S. |
| * futureValueType(Future<S>) = S, for all S. |
| * futureValueType(FutureOr<S>) = S, for all S. |
| * futureValueType(void) = void. |
| * futureValueType(dynamic) = dynamic. |
| * Otherwise, for all S, futureValueType(S) = Object?. |
| * |
| * @description Check that it is an error if type of return value is not |
| * assignable to the future |
| * |
| * @author sgrekhov@unipro.ru |
| */ |
| |
| Future<num?> foo() async { |
| return new Future<dynamic>.value(42); |
| // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| } |
| |
| main() { |
| foo(); |
| } |
