;;;; The context allocator holds an Allocator value, incarnation and all. Here
;;;; the inner with-allocator destroys the arena the outer one installed, and
;;;; on the way out the outer one is put back; the next arena-new takes the
;;;; destroyed arena's record. Allocating from the context must then trap,
;;;; not quietly allocate from the new arena. Argument 1 reads context/allocator
;;;; as a value first and uses that instead, which traps the same way.
(defn main [args [str]] i32
  (let [which (if (> (length args) 1) (bytes->i64 (bytes-view (at args 1))) 0)
        a (arena-new 4096)]
    (with-allocator a
      (let [held context/allocator]
        (with-allocator (heap-allocator)
          (arena-destroy a))
        (let [b (arena-new 4096)
              w (vec-new i32 b)]
          (push w 5)
          (println (at w 0))
          (if (= which 1)
            (let [v (vec-new i32 held)] (push v 1))
            (let [v (vec-new i32)] (push v 1)))
          (println "unreachable")))))
  0)