module CCPersistentArray:sig..end
From the paper by Jean-Christophe Filliâtre,
"A persistent Union-Find data structure", see
 the ps version
Since 0.10
type 'a t 
val make : int -> 'a -> 'a tmake n x returns a persistent array of length n, with x. All the
    elements of this new array are initially physically equal to x
    (in the sense of the == predicate). Consequently, if x is mutable, it is
    shared among all elements of the array, and modifying x through one of the
    array entries will modify all other entries at the same time.Invalid_argument if n < 0 or n > Sys.max_array_length.
    If the value of x is a floating-point number, then the maximum size is
    only Sys.max_array_length / 2.val init : int -> (int -> 'a) -> 'a tmake n f returns a persistent array of length n, with element
    i initialized to the result of f i.Invalid_argument if n < 0 or n > Sys.max_array_length.
    If the value of x is a floating-point number, then the maximum size is
    only Sys.max_array_length / 2.val get : 'a t -> int -> 'aget a i returns the element with index i from the array a.Invalid_argument "index out of bounds" if n is outside the
    range 0 to Array.length a - 1.val set : 'a t -> int -> 'a -> 'a tset a i v sets the element index i from the array a to v.Invalid_argument "index out of bounds" if n is outside the
    range 0 to Array.length a - 1.val length : 'a t -> intval copy : 'a t -> 'a tcopy a returns a fresh copy of a. Both copies are independent.val map : ('a -> 'b) -> 'a t -> 'b t
val mapi : (int -> 'a -> 'b) -> 'a t -> 'b tmapi,
    the function is also given the index of the element.
    It is equivalent to fun f t -> init (fun i -> f (get t i)).val iter : ('a -> unit) -> 'a t -> unit
val iteri : (int -> 'a -> unit) -> 'a t -> unititer f t applies function f to all elements of the persistent array,
    in order from element 0 to element length t - 1.val fold_left : ('a -> 'b -> 'a) -> 'a -> 'b t -> 'a
val fold_right : ('a -> 'b -> 'b) -> 'a t -> 'b -> 'bval append : 'a t -> 'a t -> 'a tval flatten : 'a t t -> 'a tval flat_map : ('a -> 'b t) ->
       'a t -> 'b tval to_array : 'a t -> 'a arrayto_array t returns a mutable copy of t.val of_array : 'a array -> 'a tfrom_array a returns an immutable copy of a.val to_list : 'a t -> 'a listto_list t returns the list of elements in t.val of_list : 'a list -> 'a tof_list l returns a fresh persistent array containing the elements of l.val of_rev_list : 'a list -> 'a tof_rev_list l is the same as of_list (List.rev l) but more efficienttype'asequence =('a -> unit) -> unit
type'agen =unit -> 'a option
val to_seq : 'a t -> 'a sequence
val of_seq : 'a sequence -> 'a t
val of_gen : 'a gen -> 'a tval to_gen : 'a t -> 'a gentype'aprinter =Format.formatter -> 'a -> unit
val print : 'a printer ->
       'a t printer