module Set_once

: sig

This module implements an option ref that starts out as None, and may be set only once. If one tries to set it twice a run time error is generated.

exception Already_set

type 'a t

val create : unit -> 'a t

val set : 'a t -> 'a -> (unit, string) Result.t

val set_exn : 'a t -> 'a -> unit

val get : 'a t -> 'a option

val get_exn : 'a t -> 'a

val t_of_sexp : (Sexplib.Sexp.t -> 'a) -> Sexplib.Sexp.t -> 'a t

val sexp_of_t : ('a -> Sexplib.Sexp.t) -> 'a t -> Sexplib.Sexp.t

val bin_t : 'a Bin_prot.Type_class.t -> 'a t Bin_prot.Type_class.t

val bin_read_t : 'a Bin_prot.Read.reader -> 'a t Bin_prot.Read.reader

val __bin_read_t__ : 'a Bin_prot.Read.reader -> (int -> 'a t) Bin_prot.Read.reader

val bin_reader_t : 'a Bin_prot.Type_class.reader -> 'a t Bin_prot.Type_class.reader

val bin_size_t : 'a Bin_prot.Size.sizer -> 'a t Bin_prot.Size.sizer

val bin_write_t : 'a Bin_prot.Write.writer -> 'a t Bin_prot.Write.writer

val bin_writer_t : 'a Bin_prot.Type_class.writer -> 'a t Bin_prot.Type_class.writer

end