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// A: AHE
// B: AHEImpl
// C: AGE
// D: KGroup
// E: KList
// F: KPoint
// S: parent type
// T: child type
import java.util.*;
interface A<S extends C>
{
public void foo();
}
abstract class B<S extends C> implements A<S>
{
}
class C<S extends C, T extends A> extends B<S>
{
public void foo()
{
}
public Collection<T> get()
{
return new ArrayList<T>();
}
}
class D<S extends C, T extends C> extends C<S,T>
{
}
class E<T extends F> extends C<D,T>
{
public void bar()
{
for(T t : this.get()) {}
for(F f : this.get()) {}
// This is OK, though it gets marked as unsafe.
E<F> e1 = new E();
for(F f : e1.get()) {}
// But this fails to compile!
E e2 = new E();
for(F f : e2.get()) {}
/*
javac fails with this error:
found : java.lang.Object
required: F
for(F f : e2.get()) {}
^
In principle, it should know that E is always E<? extends F>,
because it says so right there in the class definition.
But it seems to think plain old E is E<Object>, even though
that should be disallowed.
At the very least, it seems like it should erase to E<A>,
which is the bound on the superclass C.
Mac OS X 10.4.8, build 8L2127
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-112)
Java HotSpot(TM) Client VM (build 1.5.0_06-64, mixed mode, sharing)
*/
}
}
interface F extends A<E>
{
}
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