Re: User defined I/O conversion casts

Tom Lane wrote:
> Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
>> Yeah, a magical OID clearly has some issues. A new field in pg_cast is
>> the obvious alternative. How about adding a "castmethod" char field,
>> with values:
>> b = binary-compatible cast (CREATE CAST ... WITHOUT FUNCTION)
>> i = I/O coercion cast (the new beast, CREATE CAST ... WITH INOUT)
>> f = use cast function specified in castfunc field.
>> castfunc is 0 for methods b and i.
>
> Seems sane to me. If you do that, please add a check in the opr_sanity
> regression test that castfunc is nonzero if and only if castmethod is f.

Here's a patch. It seems pretty straightforward, I'll apply this
tomorrow, barring objections. Note to self: bump the catalog version.

BTW, it looks like we don't have any test cases for the CREATE CAST
command. I think I'll add one.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com