Should be able to do this now.
#3 and #10 are waiting on this.
This is done, but is blocking on a Parrot bug: https://trac.parrot.org/parrot/ticket/909
Another option is to do our own metaclass which could maybe tie in with #33.
My work on this has been pushed as the iss34 branch.
Now waiting-on #41 for ditching P6object.
And the iss34 branch has been merged into iss41, so that's where it's happening now.