n_distinct doesn't work as expected with lists

[idmn]

Consider this example:

x <- list(NULL, 1, 1)
length(unique(x))    
#> [1] 2

But:

dplyr::n_distinct(x)        
#> [1] 3

[krlmlr]

Is this a duplicate of #2355?

[romainfrancois]

It's the same problem yes.

[lock]

This old issue has been automatically locked. If you believe you have found a related problem, please file a new issue (with reprex) and link to this issue. https://reprex.tidyverse.org/