in reply to
Triggering 'strict' from within a package
Perhaps I am a bit late in the game here to answer your question, especially after such astute answers from tye and Abigail-II. However, with any case of trying to make "meta" declarations from outside the lexical space I would use a source filter to tack the appropriate boilerplate code to the begining of the file prior to it being parsed.
Light a man a fire, he's warm for a day. Catch a man on fire, and he's warm for the rest of his life. - Terry Pratchet