Or use a source filter ;)

There is a fourth option. You could choose to step away from the threads API and invent your own sub. A sub that takes a reference but has a different name. I don't know of a good name, but let's call it refshare for now. This can be combined with supporting share with the new prototype on newer perls. On older perls you could croak 'Old perl needs refshare(\$foo) instead of share($foo)'.

This has one froblem: s/use forks;/use threads;/ no longer magically makes the program use real threads. But a third module (threads::forks?) could implement a refshare that calls the real share to solve that problem.

Juerd # { site => 'juerd.nl', plp_site => 'plp.juerd.nl', do_not_use => 'spamtrap' }