Function/Constant autoloading

Hi, Maybe this topic occured already, then sorry when I'm wasting your time, but I'm wondering, why there is no autoloading for functions and (namespace)constants. When a class is not found, then an userland function is called. Thus I don't see a reason, why something like this doesn't exists for functions and (namespace)constants too, because using them is quite uncomfortable right now compared to classes and the decision _how_ to load them would be on the developers-side anyway. Sebastian Krebs