Proposal: Avoid non-tail recursion

[Will-Low]

Given that the Rust compiler does not current implement tail-call optimization, I think it would make sense to include non-tail recursion as an antipattern. Would folks agree?

Would it also make sense that, instead of rolling one's own tail-recursive functions, that we recommend the use of the fold method, which uses tail recursion?

[pickfire]

There are library that allows using tail recursion with macro, I forgot which one.