// Copyright (c) 2020, 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 Nullable: if T1 is S1? then:
 *  T0 <: T1 iff any of the following hold:
 *  either T0 <: S1
 *  or T0 <: Null
 *  or T0 is X0 and X0 has bound S0 and S0 <: T1
 *  or T0 is X0 & S0 and S0 <: T1
 * @description Check that if type T1 is S1? and T0 <: S1 then T0 is subtype of
 * T1.
 * @author sgrekhov@unipro.ru
 */
/**
 * @description Check that if type T0 is a subtype of a type T1, then instance
 * of T0 can be be used as a return value of type T1
 * @author sgrekhov@unipro.ru
 */
/*
 * This test is generated from right_nullable_A01.dart and 
 * return_value_x01.dart.
 * Don't modify it. If you want to change this file, change one of the files 
 * above and then run generator.dart to regenerate the tests.
 */


import '../../utils/common.dart';

class S1 {
  const S1();
}
class T0 extends S1 {}

T0 t0Instance = new T0();
S1? t1Instance = new S1();

const t1Default = const S1();


S1? returnValueFunc() => forgetType(t0Instance);

class ReturnValueTest {
  static S1? staticTestMethod() => forgetType(t0Instance);

  S1? testMethod() => forgetType(t0Instance);

  S1? get testGetter => forgetType(t0Instance);
}

class ReturnValueGen<X> {
  X testMethod() => forgetType(t0Instance);
  X get testGetter => forgetType(t0Instance);
}


main() {
  S1? returnValueLocalFunc() => forgetType(t0Instance);

  returnValueFunc();
  returnValueLocalFunc();

  ReturnValueTest.staticTestMethod();

  new ReturnValueTest().testMethod();
  new ReturnValueTest().testGetter;

  // Test type parameters

  //# <-- NotGenericFunctionType
  new ReturnValueGen<S1?>().testMethod();
  new ReturnValueGen<S1?>().testGetter;
  //# -->
}