// 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:
/// Left Nullable: if T0 is S0? then:
/// - T0 <: T1 iff S0 <: T1 and Null <: T1
/// @description Check that if type T0 is S0? and S0 <: T1 and Null <: T1 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 left_nullable_A01.dart and 
/// return_value_x01.dart.
/// Don't modify it. If you want to change this test, change one of the files 
/// above and then run generator.dart to regenerate the tests.


class T1 {
  const T1();
}
class S0 extends T1 {
  const S0();
}

S0? t0Instance = new S0();
T1? t1Instance = new T1();

const t1Default = const T1();


T1? returnValueFunc() => t0Instance;

class ReturnValueTest {
  static T1? staticTestMethod() => t0Instance;

  T1? testMethod() => t0Instance;

  T1? get testGetter => t0Instance;
}

main() {
  T1? returnValueLocalFunc() => t0Instance;

  returnValueFunc();
  returnValueLocalFunc();

  ReturnValueTest.staticTestMethod();

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

}