It's either "fearless concurrency for highly scalable applications" or panic. Your threads will panic. They will throw exceptions. You will end up dividing by

It's either "fearless concurrency for highly scalable applications" or panic. Your threads will panic. They will throw exceptions. You will end up dividing by zero at 3 AM on a Christmas. If your own answer to exceptions is "yeah, the program just crashes and burns", you're doing everything wrong. It took Go and Rust over a decade to realise that and add poor man's excuses for handling panic. But exceptions are inevitable, and your language must provide good ways of dealing with them. See Erlang's approach for how to do it right.