Thanks for the explanation. I guess most languages need this feature i.e. fail anywhere below this call, then return the type error + where it occurred + a stack trace. I've even heard of people doing stuff like that in C, where they store the stack trace in a list they populate and return errors as part of the same struct, in order to have something similar to exceptions.

I have to say I really enjoyed Rust when it was in its infancy (version 0.1 - 0.2 or thereabouts), but have since fallen off. It used to be so simple and so clean, and unlike anything else. Today it's just way to complex for me :-)