user=> (defn fun [&[x y :as lst]] [x y])
#'user/fun
user=> (fun 1 2)
[1 2]
user=> (fun '(1 2))
[(1 2) nil]

AS OPPOSED TO

user=> (defn fun ([x y] [x y]) ([[x y]] [x y]))
#'user/fun
user=> (fun 1 2)
[1 2]
user=> (fun '(1 2))
[1 2]