Hi basiliscos,

Thanks for your response. Just to clarify: The values I'm looking at are not under my control. They are normally supposed to be numbers, strings, or objects that stringify to something useful, like for example Path::Class objects. Those values will be stringified and used as an argument to an external command, which is why I make the assumption that references, which would be stringified to something like "HASH(0x9c5d2d9)", are probably a mistake on the user's part, and I'd like to provide a warning for those cases. I've posted my current solution below.

Thanks and Regards,
-- Hauke D