Note that we don't run into problems until we start introducing prototypes, which generally people say to "stay away from", which is fine, but with caveats...
Well... that's what prototypes are meant for: breaking the rules, and that entails you're taking the risk of confusing the users of your library, the perl parser, or both.
You can only 'stay away' from something for so long, and then finally you want to become one of those mythical people who 'really really really know what they are doing'
I understand your concern, but I can only repeat the above paragraph. The phrase "enough rope to hang yourself" comes to mind.