This is exactly what happens if you think you have a 32 bit int but actually have a 64 bit int

Yes - which demonstrates that you need to know what you have. I'm in agreement with that - and have been right from the beginning. It's just that I don't see a need to establish anything other than that wrt Digest::JHash. And, given that that info can easily be derived by (or passed to) the pre-processor, you can tailor jhash() to efficiently deal with any scenario.

But maybe I'm being blind to certain issues ... so I'll just butt out. I look forward to the next release of Digest::JHash, where I get to see how you eventually do deal with the issue :-)

Cheers,
Rob