Ruby has even() and odd() for sure, I have used Ruby for some years. And I saw isOdd() isEven() in Rust API docs, but I am not sure if that was a extern crate (package).
Of course it is an old joke that that some people created packages which contained only the odd()/even() functions. But that is absolutely no reason to refuse to adding these functions to Nims std lib. As the procs are tiny and with "is" prefix there is no risk of name space pollution.
