about
> OK. But I shouldn't need to. if x /= Void is supposed to be a CAP.
  if attribute_x /= Void then
     attribute_x.do_something   
is not a CAP  (unless attribute_x is "stable", but let's not use that in new void-safe code)

however
   if attached attribute_x as l_x then
       l_x.do_something
is a CAP
same as 
  if local_x /= Void then
     local_x.do_something

so here, I don't see the trouble