Module type Async_extra.Persistent_singleton.S

type persistent_singleton

val load : string ‑> default:persistent_singleton ‑> persistent_singleton Core.Or_error.t Import.Deferred.t

val load' : string ‑> default:persistent_singleton ‑> [ `Ok of persistent_singleton | `Can_not_load_due_to_unclean_shutdown | `Can_not_determine_whether_file_exists ] Import.Deferred.t

val load_exn : string ‑> default:persistent_singleton ‑> persistent_singleton Import.Deferred.t

val save : string ‑> value:persistent_singleton ‑> unit Import.Deferred.t