Apparent generics compilation bug new to Java 1.7

[Benedict Elliott Smith]

I'm not using I and I2 interchangeably, I'm just swapping them when
declaring a new binding for the type parameters of (a different) A.

i.e. let's call the class definition A, and the type I am declaring for the
method return value A' ; and its corresponding type parameters K', V', I'
and I2'

All I am saying is that K' ^= V, V' ^= K, I' ^= I2 and I2' ^= I

Now, I2 ^= "?" extends B<V, K> and I ^= "?" extends B<K, V>

(now ignoring the ? extends for brevity...)

Since K' ^= V and V' ^= K; we have I' == I2 == B<K',V'> and I2' == I ==
B<V',K'>

Which looks fine to me. Could you clarify your argument if I'm missing
something?







On 23 February 2012 14:46, Florian Weimer <fweimer at bfk.de> wrote:

> * Benedict Elliott Smith:
>
> > The below class no longer compiles (1.7.02); I can't see any good reason
> > for it not to, and nor can ecj or the 1.6 JDK, so I think it is quite
> > probably a bug.
>
> Why are I and I2 interchangeable?
>
> > public class TypeTest {
> >  static abstract class A<K, V, I extends B<K, V>, I2 extends B<V, K>> {
> >  abstract A<V, K, I2, I> test();
> >  }
> >  static class B<K, V> {
> >  }
> > }
>
> They have different bounds, so I think you can't swap them.
>
> --
> Florian Weimer                <fweimer at bfk.de>
> BFK edv-consulting GmbH       http://www.bfk.de/
> Kriegsstraße 100              tel: +49-721-96201-1
> D-76133 Karlsruhe             fax: +49-721-96201-99
>
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