module StdLabels:sig..end
   This meta-module provides labelized version of the Array,
   Bytes, List and String modules.
   They only differ by their labels. Detailed interfaces can be found
   in arrayLabels.mli, bytesLabels.mli, listLabels.mli
   and stringLabels.mli.
module Array: ArrayLabels
module Bytes: BytesLabels
module List: ListLabels
module String: StringLabels