perl_uuid_t*                    T_PV
uuid_context_t*         T_PTRUUID
INPUT
T_PTRUUID
        if (SvROK($arg) && sv_derived_from($arg, \"Data::UUID\")) {
            IV tmp = SvIV((SV*)SvRV($arg));
            $var = INT2PTR($type,tmp);
        }
        else
            croak(\"$var is not of type Data::UUID\")
OUTPUT
T_PTRUUID
        sv_setref_pv($arg, \"Data::UUID\", (void*)$var);