# Module Std.Posix_clock

    module Posix_clock: Posix_clock

    type t =

`|` | `Realtime`
`|` | `Monotonic`
`|` | `Process_cpu`
`|` | `Process_thread`

    val all : t list

    val to_string : t -> string

    val getres : (t -> Core.Std.Int63.t) Core.Std.Or_error.t

    val gettime : (t -> Core.Std.Int63.t) Core.Std.Or_error.t

    val min_interval : (t -> Core.Std.Int63.t) Core.Std.Or_error.t

    val mean_gettime_cost : (measure:t -> using:t -> Core.Std.Int63.t)
           Core.Std.Or_error.t

    module Time_stamp_counter: sig .. end