LanguageFeatures/Subtyping/static/test_types/right_promoted_variable_A01.dart

// 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 Promoted Variable: if T1 is a promoted type variable X1 & S1 then:
/// - T0 <: T1 iff T0 <: X1 and T0 <: S1
/// @description Check that if type T1 is a promoted type variables X1 & S1 and
/// T0 <: X1 and T0 <: S1 then T0 is a subtype of T1.
/// @author sgrekhov@unipro.ru

class X1 {
  const X1();
}
class S1 extends X1 {
  const S1();
}

class T0 extends S1 {}
//# @T0 = T0
//# @T1 = S1

T0 t0Instance = new T0();
X1 t1Instance = new S1();

const t1Default = const S1();

//# <!-- Global variables & classes definition -->

main() {
  X1 t1Instance = new S1();
  if (t1Instance is S1) {
    //# <!-- Test body -->
  }
}