Re: Implementing an operator in C?

Am Sonntag, 4. Februar 2001 20:12 schrieben Sie:
> Mario Weilguni <mweilguni(at)sime(dot)com> writes:
> > float8 num3 = numeric_float8(num1);
>
> That won't work in the brave new world of 7.1 :-(. You need to do
> something like
>
> float8 num3 = DatumGetFloat8(DirectFunctionCall1(numeric_float8,
> NumericGetDatum(num1)));
>
> Ugly, I know ... but we have to be rigidly careful about converting
> values to Datum and back in order to avoid portability problems.
>
> A decent C compiler should've warned about type mismatches in your call,
> BTW.
>
> regards, tom lane

Thanks alot for the info, but the problem is elsewhere. Even a simple
function like
Datum
nef(PG_FUNCTION_ARGS)
{
         Numeric                 num1 = PG_GETARG_NUMERIC(0);
         PG_RETURN_BOOL(true);
}

will crash. The macro PG_GETARG_NUMERIC evaluates to:
((Numeric)pg_detoast_datum((struct varlena *) ((Pointer) ( (fcinfo->arg[0])))
and this pg_detoast_datum will lead to a crash (SIGSEGV). So I think I must
be doing something wrong here, isn't it?

Thanks!

Best regards,
         Mario Weilguni

--
===================================================
Mario Weilguni                 KPNQwest Austria GmbH
 Senior Engineer Web Solutions Nikolaiplatz 4
 tel: +43-316-813824         8020 graz, austria
 fax: +43-316-813824-26       http://www.kpnqwest.at
 e-mail: mario(dot)weilguni(at)kpnqwest(dot)com
===================================================