Function array_nelems_size

src/backend/utils/adt/arrayfuncs.c:4803–4809

* Compute total size of the nitems array elements starting at *ptr * * Parameters same as for array_seek */

 * Parameters same as for array_seek
 */
static int
array_nelems_size(char *ptr, int offset, bits8 *nullbitmap, int nitems,
				  int typlen, bool typbyval, char typalign)
{
	return array_seek(ptr, offset, nullbitmap, nitems,
					  typlen, typbyval, typalign) - ptr;
}

/*
 * Copy nitems array elements from srcptr to destptr