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import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;
class WildcardSubtype {
class MyClass {}
class Visitor<T> {
String visit(T p) {
return "";
}
}
class MyClassVisitor extends Visitor<@Nullable MyClass> {}
class NonNullMyClassVisitor extends Visitor<@NonNull MyClass> {}
void test(MyClassVisitor myClassVisitor, NonNullMyClassVisitor nonNullMyClassVisitor) {
// :: error: (argument.type.incompatible)
take(new Visitor<@Nullable Object>());
// :: error: (argument.type.incompatible)
take(new Visitor<@Nullable Object>());
Visitor<?> visitor1 = myClassVisitor;
Visitor<?> visitor2 = nonNullMyClassVisitor;
// :: error: (assignment.type.incompatible)
Visitor<? extends @NonNull Object> visitor3 = myClassVisitor;
Visitor<? extends @NonNull Object> visitor4 = nonNullMyClassVisitor;
// :: error: (assignment.type.incompatible)
Visitor<? extends @NonNull Object> visitor5 = new MyClassVisitor();
// :: error: (assignment.type.incompatible)
Visitor<? extends @NonNull Object> visitor6 = new MyClassVisitor();
// :: error: (argument.type.incompatible)
take(new MyClassVisitor());
// :: error: (argument.type.incompatible)
take(new MyClassVisitor());
}
void take(Visitor<@NonNull ? extends @NonNull Object> v) {}
void bar() {
// :: error: (argument.type.incompatible)
take(new Visitor<@Nullable Object>());
// :: error: (argument.type.incompatible)
take(new MyClassVisitor());
}
void baz() {
// :: error: (argument.type.incompatible)
take(new MyClassVisitor());
take(new NonNullMyClassVisitor());
}
}
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