m/conform landed in master by @nilern! #343 will change the names to m/parse and m/parser:

(m/parse
  [:* [:cat*
       [:prop string?]
       [:val [:alt*
              [:s string?]
              [:b boolean?]]]]]
  ["-server" "foo" "-verbose" true "-user" "joe"])
;[{:prop "-server", :val [:s "foo"]}
; {:prop "-verbose", :val [:b true]}
; {:prop "-user", :val [:s "joe"]}]