qc.clj

(defn qc
  [op]
  (fn [coll]
    (if (not= (count coll) 2)
      (throw (IllegalArgumentException. "coll must have length 2.")))
    (if (odd? (first coll))
      (throw (IllegalArgumentException. "first elem must be even.")))
    (if (even? (second coll))
      (throw (IllegalArgumentException. "second elem must be odd.")))
    (apply op coll)))
  

(def f1 (qc +))
(def f2 (qc -))
(def f3 (qc /))