Honestly, I'd probably just teach them how it works in general and when they
crash into this issue, explain why it doesn't work here.
UFCS can be used if the left argument is something that by itself has a type.
Unfortunately, Nim still doesn't have first-class iterators, which is the
reason why you can't use UFCS on them.
> UFCS can be used if the left argument is something that by itself has a type
That is more or less how I think about it when programming Nim. Is that
phrasing how you would recommend teaching newcomers about UFCS?
What's your workflow to know what you can and cannot use UFCS on? And
especially how do you teach newcomers UFCS? I am tempted to err on the side of:
* Use an IDE (like alaviss' nvim plugin) that shows you the type of what
you're writing, and then
* Only use UFCS for procs and funcs and NOTH
