(end1 (or end1 len1))
(end2 (or end2 len2))
(replace-len (min (- end1 start1) (- end2 start2))))
- ,(unless (policy node (= safety 0))
+ ,(unless (policy node (= insert-array-bounds-checks 0))
`(progn
(unless (<= 0 start1 end1 len1)
(sequence-bounding-indices-bad-error seq1 start1 end1))
`(apply
(lambda ,vars
(declare (ignorable ,@vars))
+ (declare (optimize (insert-array-bounds-checks 0)))
(let* ((.length. (+ ,@lengths))
(.pos. 0)
(.string. (make-string .length. :element-type ',element-type)))