transient + core.async

async-transient.clj

; Is there a way to tell assoc! "No really, I know what I'm doing."
; Do I know what I'm doing?
(->> (async/to-chan [[:a 1] [:b 2] [:c 3]])
     (async/reduce (fn [acc [k v]] 
                      (assoc! acc k v))
                   (transient {}))
     (async/map< persistent!)
     (async/<!!))
;=>
; Exception in thread "async-dispatch-52" java.lang.IllegalAccessError: Transient used by non-owner thread
;	at clojure.lang.PersistentArrayMap$TransientArrayMap.ensureEditable(PersistentArrayMap.java:449