Get IPs in OCaml (using only stdlib)

ips.ml

module StringSet = Set.Make(String)

let addr_to_string = function
    | Unix.ADDR_UNIX s           -> s
    | Unix.ADDR_INET (iaddr, _)  -> Unix.string_of_inet_addr iaddr

let get_local_ips () =
    Unix.getaddrinfo "localhost" "" []
    |> List.map (fun x -> x.Unix.ai_addr)


let () =
    get_local_ips()
    |> List.map addr_to_string
    |> StringSet.of_list 
    |> StringSet.iter print_endline