Re-export := with use_tidy_eval

[jonthegeek]

:= (the tidyeval assignment operator, which I pronounce "digested is") is often as useful for tidyeval as the functions exported by the file generated via usethis::use_tidyeval(). It would be helpful if it were also re-exported.

[hadley]

But it doesn't actually do anything?

[jonthegeek]

Don't you need it when there's tidyeval on the LHS of a parameter assignment? When I do that, cran checks complain about := until/unless I at least import.

[hadley]

Yeah, it's just a syntactic operation so the := function is never actually called (IIRC). But if R CMD check has a problem with it, we should include. @jonthegeek do you want to do a PR?

[jonthegeek]

Sure, I can probably knock this out tonight.

[jennybc]

Ironically I am getting this exact NOTE in a usethis branch, due to my use of :=.

[jennybc]

I think we need to think separately about the need for @importFrom rlang := vs. the need to re-export it. cc @lionel-

[lionel-]

Reexporting it in our packages will give a useful error message when := is used in a wrong context, so that seems helpful.