Problem with type-casting to interface arrays

[Vladimir Panteleev]

Hi,

With an interface I and an implementation C : I, is this code sane?

     C[] c = [new C()];
     I[] i = cast(I[]) c;

Currently, any attempts to do this typecast fail for me (the objects inside i are corrupted/unusable).
I don't see why it should fail (per the spec), so I'm inclined to believe it's a compiler bug.

I've attached three test cases (simple Phobos, Phobos, Tango).

EDIT: Someone has explained to me why does this happen, and that I simply cannot do this because that's how things work. Interface Vtable offsets and such - it would have to create a copy to do this (adjust pointers and such). Still, I think it's just too easy to fall for this - and it's hard to figure out a cause for such a bug. The compiler should at least return null for such a typecast - and, in the best case, display a warning or error.

-- 
Best regards,
  Vladimir                          mailto:thecybershadow at gmail.com
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