Must_use and linear types

[gbutler]

@vi0

Does drop(must_use_ret())

I would say that is a NO.

@vi0

s passing to user-defined function (that unfortunately forgots to use its argument) considered using it?

Yes. Unless the #[must_use] indicates that only specific methods constitute "usage" in that context. (see my EDIT's on my original comment above where I elaborate).