Richard Huxton <dev@archonet.com> writes:
> Tom Lane wrote:
>> You could do that in C, but none of the available PLs support it.
> How would you define the signature for the function? One parameter of
> type anyelement?
Type RECORD would be a better choice --- ANYELEMENT allows scalar types
which is not what you want here. (You could probably still do it with
a function declared that way, but it'd have to take extra steps to
defend itself against being passed, say, an integer.)
If you're looking for a coding model, stripping down record_out() to
just count nulls should get you there.
regards, tom lane