module Set_once: sig .. end
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.Unsafe_read_c.reader -> 'a t Bin_prot.Read_ml.reader
val bin_read_t_ : 'a Bin_prot.Unsafe_read_c.reader ->
'a t Bin_prot.Unsafe_read_c.reader
val bin_read_t__ : 'a Bin_prot.Unsafe_read_c.reader ->
(int -> 'a t) Bin_prot.Unsafe_read_c.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.Unsafe_write_c.writer -> 'a t Bin_prot.Write_ml.writer
val bin_write_t_ : 'a Bin_prot.Unsafe_write_c.writer ->
'a t Bin_prot.Unsafe_write_c.writer
val bin_writer_t : 'a Bin_prot.Type_class.writer -> 'a t Bin_prot.Type_class.writer