Peter Eisentraut <peter_e@gmx.net> writes:
> I'm not wedded to it, I just modelled it after the SQL standard, but
> evidently the volatility levels are different in detail. I would disallow
> volatile casts in any case. There ought to be a minimal behavioral
> contract between creators and users of types.
Shrug ... ISTM the behavior of a type is whatever the type creator says
it should be. Whether a volatile cast is a good idea is dubious
(I can't think of any good examples of one offhand) but I don't see the
argument for having the system restrict the type creator's choices.
regards, tom lane