;;;; (Some nil), the run-time half -- M2 queue item 4.
;;;;
;;;; The literal (Some nil) is refused at compile time (test_flan.ml). This is
;;;; the other half: a dyn value the checker cannot see is nil until the
;;;; program runs, reaching Some anyway. flan_dyn_need_not_nil owns the
;;;; wording, the same way flan_dyn_need_i64 owns dyn-boundary.flan's.

(defn maybe-nil [flag bool] dyn (if flag 5 nil))

(defn main [] ()
  (print (match (Some (maybe-nil true)) (Some x) x None -1))
  (println "")                                          ; 5
  (print (match (Some (maybe-nil false)) (Some x) x None -1))
  (println ""))