Robert Nystrom
48608ce9bc
Change-Id: I8e21f82dc241a63f78fb1f6a25669b1aa633788c Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/152080 Commit-Queue: Bob Nystrom <rnystrom@google.com> Auto-Submit: Bob Nystrom <rnystrom@google.com> Reviewed-by: Leaf Petersen <leafp@google.com>
50 lines
1.5 KiB
Dart
50 lines
1.5 KiB
Dart
// Copyright (c) 2019, 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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// Tests subclass usage for the `in` variance modifier.
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// SharedOptions=--enable-experiment=variance
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typedef CovFunction<T> = T Function();
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typedef ContraFunction<T> = void Function(T);
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class Covariant<out T> {}
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class Contravariant<in T> {}
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mixin MContravariant<in T> {}
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class A<in T> extends Contravariant<T> {}
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class B<in T> implements Contravariant<T> {}
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class C<in T> with MContravariant<T> {}
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class D<in T> extends Covariant<Contravariant<T>> {}
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class E<in T> extends Contravariant<Covariant<T>> {}
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class F<in T> extends Covariant<ContraFunction<T>> {}
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class G<in T> extends Covariant<ContraFunction<CovFunction<T>>> {}
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class H<in T> extends Covariant<CovFunction<ContraFunction<T>>> {}
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class I<in T> extends Covariant<ContraFunction<Covariant<T>>> {}
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class J<in T> extends Contravariant<Contravariant<Contravariant<T>>> {}
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class K<in T> = Contravariant<T> with MContravariant<T>;
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class L<in T> = Covariant<Contravariant<T>> with MContravariant<T>;
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class M<in T> = Contravariant<T> with MContravariant<Covariant<T>>;
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main() {
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A<num> a = A();
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B<num> b = B();
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C<num> c = C();
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D<num> d = D();
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E<num> e = E();
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F<num> f = F();
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G<num> g = G();
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H<num> h = H();
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I<num> i = I();
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J<num> j = J();
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K<num> k = K();
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L<num> l = L();
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M<num> m = M();
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}
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