"Pavel Stehule" <pavel.stehule@gmail.com> writes:
> Is possible casting domain?
No, because find_coercion_pathway() expects that only base types are
listed in pg_cast, so it starts by stripping domains. Function lookup
tends to do that too, so it's hard even to declare a function as taking
a domain.
Elein was going to look into devising a more domain-friendly set of
type coercion rules, but I dunno if she's made any progress.
regards, tom lane