Robert Nystrom
3b646d61d5
Change-Id: I464f1209211d5eaf99395d2d4825467e9cf574a0 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/148947 Commit-Queue: Bob Nystrom <rnystrom@google.com> Reviewed-by: Erik Ernst <eernst@google.com>
25 lines
561 B
Dart
25 lines
561 B
Dart
// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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import "package:expect/expect.dart";
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class B {}
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class A {
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B? x, y;
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// Promotion occurs for the initializing formal because C <: B.
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A(this.x) : y = (x is C) ? x.x : x;
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}
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class C extends A implements B {
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C(B? x) : super(x);
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}
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main() {
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C c = new C(null);
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C cc = new C(c);
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Expect.equals(c.y, null);
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Expect.equals(cc.y, null);
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}
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