I'm currently working around this problem by assuming that a Closure implements `__invoke`:
`$this->someProp->__invoke();` Not really nice, but this works in both 5.3 and 5.4. If the suggestion above could cover also `callable` and not just `Closure` then it would be quite interesting to have that. Marco Pivetta http://twitter.com/Ocramius http://ocramius.github.com/
