setdiff does not seem to like integer64 class vectors

[aaronw22]

A trivial example:

> setdiff(bit64::as.integer64(c(1, 2, 3)), bit64::as.integer64(c(1, 2)))
[1] 1.482197e-323

> # Expected result
> setdiff(c(1L, 2L, 3L), c(1L, 2L))
[1] 3

My sessionInfo()

R version 4.3.0 (2023-04-21 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19045)

Matrix products: default


locale:
[1] LC_COLLATE=English_Australia.utf8  LC_CTYPE=English_Australia.utf8    LC_MONETARY=English_Australia.utf8 LC_NUMERIC=C                      
[5] LC_TIME=English_Australia.utf8    

time zone: Australia/Sydney
tzcode source: internal

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] bit64_4.0.5 bit_4.0.5  

loaded via a namespace (and not attached):
[1] compiler_4.3.0    tools_4.3.0       rstudioapi_0.15.0

[psychelzh]

Currently, there is only match.integer64(). As users, we need to write our own set operations for bit64.

[aaronw22]

Makes sense, so it is a missing method issue rather than a bug.

[truecluster]

Explanation: if setdiff was a generic, we could write a method for integer64. But it would dispatch only on the first argument, not on the second (like match does). Current setdiff uses as.vector, but CRAN maintainers forbid a as.vector.integer64 that keeps the integer64 class attribute. We would need cooperation of CRAN maintainers to either make setdiff generic or to add special handling for integer64 to setdiff