LanguageFeatures/Subtyping/test_types/right_FutureOr_A01.dart

/*
 * Copyright (c) 2018, 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 say that a type T0 is a subtype of a type T1 (written T0 <: T1)
 * when:
 * Right FutureOr: T1 is FutureOr<S1> and
 *   either T0 <: Future<S1>
 *   or T0 <: S1
 *   or T0 is X0 and X0 has bound S0 and S0 <: T1
 *   or T0 is X0 & S0 and S0 <: T1
 * @description Check that if a type T1 is FutureOr<S1> and a type T0 is a
 * subtype of a type Future<S1>, then a type T0 is a subtype of a type T1.
 * @author ngl@unipro.ru
 */

import "dart:async";

class S1 {}
class T0 implements Future<S1> {
  asStream() => null;
  catchError(Function onError, {bool test(Object error)}) => null;
  then<T0>(FutureOr<T0> onValue(S1 value), {Function onError}) => null;
  timeout(Duration timeLimit, {FutureOr<S1> onTimeout()}) => null;
  whenComplete(FutureOr action()) => null;
}

T0 t0Instance = new T0();
FutureOr<S1> t1Instance = new Future.value(new S1());

//# @T0 = T0
//# @T1 = FutureOr<S1>