::args should be an s/cat

(s/fdef takes-a-map :args (s/cat :a ::A)))

Args is always assumed to be a list of 0 or more arguments

Or rather, a spec for a list of 0 or more arguments

So I'd like to do some spec work in an environment that needs to run on an earlier version of Clojure. I'd like to conditionally include the clojure.spec library if the Clojure version isn't 1.9 and if clojure.spec isn't already loaded. Is there an established smart pattern for doing this? Say requiring a library that does a conditional load?

I don’t know how "established" it is, but I did this for java.jdbc’s test namespace...

https://github.com/clojure/java.jdbc/blob/master/src/test/clojure/clojure/java/test_jdbc.clj#L28-L32

And the specs themselves are in a separate namespace from the code https://github.com/clojure/java.jdbc/blob/master/src/main/clojure/clojure/java/jdbc/spec.clj

An alternative approach is taken in clojure.core regarding Java versions: https://github.com/clojure/clojure/blob/d274b2b96588b100c70be065f949e1fdc9e7e14d/src/clj/clojure/core.clj#L6654-L6658

…and… https://github.com/clojure/clojure/blob/d274b2b96588b100c70be065f949e1fdc9e7e14d/src/clj/clojure/core_instant18.clj

@seancorfield: thanks! I appreciate it. I'll take a gander :)