Sorry, I answered too quickly: The second one was wrong - this one ensures c and d are contained.
(defn foo [a b & {:keys [c d] :as m}] {:pre [(every? (partial contains? m) [:c :d]]} 1) And the last one was un-idiomatic - this one checks whether only c and d are contained. (defn foo [a b & {:keys [c d] :as m}] {:pre [(empty? (dissoc m :c :d))]} 1) -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.