Signature of MethodHandleInfo.reflectAs is not specific enough

Ali Ebrahimi ali.ebrahimi1781 at
Sat Mar 1 10:17:52 UTC 2014


On Sat, Mar 1, 2014 at 12:16 AM, John Rose <john.r.rose at> wrote:

> On Feb 25, 2014, at 3:13 AM, Ali Ebrahimi <ali.ebrahimi1781 at>
> wrote:
> I know, this is too late, but I want to share my suggestion:
> public <T extends AccessibleObject&AnnotatedElement> T reflectAs(Class<?
> super T> expected, MethodHandles.Lookup lookup)
> Isn't this the same as
> public <T extends AccessibleObject> T reflectAs...
Oh, sorry, this is my bad.
I mean this:

 public <T extends AccessibleObject&Member> T reflectAs(Class<? super T>
expected, MethodHandles.Lookup lookup)

> I think we considered AccessibleObject but rejected it as not buying
> anything significant compared with Member which is an interface.
> Perhaps
> public <T extends Member & AnnotatedElement> T reflectAs...
I considered this case, but unfortunately compiler accepts following test
case with this signature:
 String ss = reflectAs(String.class, MethodHandles.lookup()); //OK!!!!!!!
This seams as compiler bug, any way with <T extends
AccessibleObject&Member> compiler catches error.

Finally, one case that compiler accepts with both signature is:

Object mo = reflectAs(Object.class, MethodHandles.lookup());

Maybe I'm wrong for this, Dan Smith can better interpret this.
T inferred to Object and T is not within its bound

Ali Ebrahimi

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