Function slot_attisnull

src/include/executor/tuptable.h:368–377

* slot_attisnull * * Detect whether an attribute of the slot is null, without actually fetching * it. */

 * it.
 */
static inline bool
slot_attisnull(TupleTableSlot *slot, int attnum)
{
	AssertArg(attnum > 0);

	if (attnum > slot->tts_nvalid)
		slot_getsomeattrs(slot, attnum);

	return slot->tts_isnull[attnum - 1];
}

/*
 * slot_getattr - fetch one attribute of the slot's contents.