;;;; The epoch trap on the pool's side. spec-memory.md, "Dev builds detect a
;;;; released region".
;;;;
;;;; This is deliberately the *other* failure from a stale handle, and the two
;;;; must not be conflated — the same rule that keeps a Vec's generation word
;;;; and its epoch word apart. A stale handle is an answer: the entity died,
;;;; resolve says None, the program carries on. A released region is not an
;;;; answer at all: the storage the pool sits in is gone, the slot array with
;;;; it, and there is nothing left to ask. So one returns None and the other
;;;; traps naming the site.
(defn main [] i32
  (let [a (arena-new 4096)]
    (let [p (pool-new i32 a)]
      (let [h (insert p 7)]
        (match (resolve p h)
          (Some x) (println (deref x))
          None     (println -1))
        ;; The region goes. p is still in scope, still looks fine, and h is
        ;; still a perfectly well-formed handle — which is exactly the case a
        ;; static rule cannot see.
        (free-all a)
        (match (resolve p h)
          (Some x) (println (deref x))
          None     (println -1)))))
  0)