# Module Time_ns.Span.Option

    module Option: sig .. end  with type span := t

    type t = private Core_kernel.Std.Int63.t

    val typerep_of_t : t Typerep_lib.Std.Typerep.t

    val typename_of_t : t Typerep_lib.Std.Typename.t

    include Identifiable

    val none : t

    val some : t -> t

    val is_none : t -> bool

    val is_some : t -> bool

    val value : t ->
           default:t -> t

    val value_exn : t -> t

    module Stable: sig .. end