val fold : ('a, 'phantom) t -> init:'acc -> f:('acc -> 'a elt -> 'acc) -> 'acc
val iter :
[ `Custom of ('a, 'phantom) t -> f:('a elt -> unit) -> unit
| `Define_using_fold ]
val length : [ `Custom of ('a, 'phantom) t -> int | `Define_using_fold ]
val iteri :
[ `Custom of ('a, 'b) t -> f:(int -> 'a elt -> unit) -> unit
| `Define_using_fold ]
val foldi :
[ `Custom of ('a, 'b) t -> init:'c -> f:(int -> 'c -> 'a elt -> 'c) -> 'c
| `Define_using_fold ]