sig
type 'a t
val empty : ('a -> int array) -> 'a FeatureTree.t
val of_list : ('a -> int array) -> 'a list -> 'a FeatureTree.t
val insert : 'a -> 'a FeatureTree.t -> 'a FeatureTree.t
val features : 'a FeatureTree.t -> 'a -> int array
val find_leq : int array -> ('a -> bool) -> 'a FeatureTree.t -> 'a
val find_leq_map : int array -> ('a -> 'b option) -> 'a FeatureTree.t -> 'b
val remove :
('a -> 'a -> bool) -> 'a -> 'a FeatureTree.t -> 'a FeatureTree.t
val rebalance : 'a FeatureTree.t -> 'a FeatureTree.t
val enum : 'a FeatureTree.t -> 'a BatEnum.t
end