| // Copyright (c) 2015, 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. |
| |
| // @dart = 2.9 |
| |
| import 'dart:async'; |
| |
| class Derived<T> implements Future<T> { |
| noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation); |
| } |
| |
| class FixedPoint<T> implements Future<FixedPoint<T>> { |
| noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation); |
| } |
| |
| class Divergent<T> implements Future<Divergent<Divergent<T>>> { |
| noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation); |
| } |
| |
| test() async { |
| // flatten(Derived<int>) = int |
| int x = await new Derived<int>(); //# 01: runtime error |
| Future<int> f() async => new Derived<int>(); //# 02: ok |
| Future<int> f() async { return new Derived<int>(); } //# 03: ok |
| Future<int> x = (() async => new Derived<int>())(); //# 04: runtime error |
| |
| // flatten(FixedPoint<int>) = FixedPoint<int> |
| FixedPoint<int> x = await new FixedPoint<int>(); //# 05: runtime error |
| Future<FixedPoint<int>> f() async => new FixedPoint<int>(); //# 06: ok |
| Future<FixedPoint<int>> f() async { return new FixedPoint<int>(); } //# 07: ok |
| Future<FixedPoint<int>> x = (() async => new FixedPoint<int>())(); //# 08: runtime error |
| |
| // flatten(Divergent<int>) = Divergent<Divergent<int>> |
| Divergent<Divergent<int>> x = await new Divergent<int>(); //# 09: runtime error |
| Future<Divergent<Divergent<int>>> f() async => new Divergent<int>(); //# 10: ok |
| Future<Divergent<Divergent<int>>> f() async { return new Divergent<int>(); } //# 11: ok |
| Future<Divergent<Divergent<int>>> x = (() async => new Divergent<int>())(); //# 12: runtime error |
| } |
| |
| main() { |
| test(); |
| } |