(define (rs-test)
  (with-heap (make-vector 40 'free)
    (init-allocator)
    (let* ([fst (gc:alloc-flat 'first)]
           [rst (gc:alloc-flat 'rest)]
;           [other (gc:alloc-flat 'pad)]
           [root (simple-root
                  (gc:cons (simple-root fst) (simple-root rst)))])
      (collect-garbage)
;      (collect-garbage)
      #;(values
       (read-root root))
       (current-heap))))