assigning numeric(0) as units gives unitless

[edzer]

I was bitten by this example:

library(units)
# udunits database from /usr/share/xml/udunits/udunits2.xml
a = 3
units(a) = NULL
a
# [1] 3
units(a) = NULL^2
a
# 3 [1]
NULL^2
# numeric(0)
units:::as_units(numeric(0))
# [1]

[Enchufa2]

Note that the last result is ok. The first argument to as_units.default is the value, and the second argument is the unit (unitless by default), so this is the expected output: a unitless empty vector.