Domains, check_violation and undefined column field in error

Hey,

I'm giving DOMAINs a shot and created a simple one with a CHECK on
PostgreSQL 9.4.4. Sadly, when the check fails, the thrown error (23514,
check_violation) doesn't seem to contain the column information in the
"c" field. Should it? Is it just not implemented?

http://www.postgresql.org/docs/9.4/static/errcodes-appendix.html says
«As of PostgreSQL 9.3, complete coverage for this feature exists only
for errors in SQLSTATE class 23 (integrity constraint violation), but
this is likely to be expanded in future.» I believe CHECK violation is
in the 23th class.

Thanks in advance!

Andri