static int internal_find(_STACK *st, void *data, int ret_val_options)
	{
	const void * const *r;
	int i;

	if(st == NULL) return -1;

	if (st->comp == NULL)
		{
		for (i=0; i<st->num; i++)
			if (st->data[i] == data)
				return(i);
		return(-1);
		}
	sk_sort(st);
	if (data == NULL) return(-1);
	r=OBJ_bsearch_ex_(&data,st->data,st->num,sizeof(void *),st->comp,
			  ret_val_options);
	if (r == NULL) return(-1);
	return (int)((char **)r-st->data);
	}