[datatable-help] (Presumably) unintended issue with data.table 1.6.3

[Timothée Carayol]

I am used to removing columns using
A <- within(A, rm(column))

However this stopped working:

> A <- data.table(a=1:10, b=11:20)
> within(A, rm(a))
Error in within.data.table(A, rm(a)) :
  Can only assign one column at a time currently via within
In addition: Warning message:
In rm(a) : object 'a' not found

transform(A, a=NULL) doesn't work either.

As a digression, is there a better way to drop a number of columns?
A[, -col] doesn't work; A[, -"col", with=F] either.

I have the latest version from CRAN I believe.

Thanks
Timothee