fread on system call producing no output should (?) return empty data.table

...as least if called with col.names and colClasses

For example, I might reasonable expect fread, when called as follows, to produce an empty data.table, instead of an error

fread(' :', colClasses=c('string','integer','integer'), col.names=c('SeqID','start','end'))

Granted it is an "edge" and "trivial" case.

But if it is easy enough to change the behavior in this case, it might save the next guy from the unexpected.

Or are my expectations not reasonable?