`sig
type t = unit t
val create_ok : unit -> t
val create_error : Unix_error.t -> t
val is_ok : t -> bool
val is_error : t -> bool
val to_result : t -> (unit, Unix_error.t) Core_kernel.Std.Result.t
val ok_exn : t -> unit
val error_exn : t -> Unix_error.t
val reinterpret_error_exn : t -> 'a t
val ok_or_unix_error_exn : t -> syscall_name:string -> unit
val ok_or_unix_error_with_args_exn :
t -> syscall_name:string -> 'a -> ('a -> Core_kernel.Std.Sexp.t) -> unit
val sexp_of_t : t -> Sexplib.Sexp.t
val compare : t -> t -> int
end`