Module type Environ.QMapS

type key
type +'a t
val empty : 'a t
val is_empty : 'a t -> bool
val mem : env -> key -> 'a t -> bool
val add : env -> key -> 'a -> 'a t -> 'a t
val remove : env -> key -> 'a t -> 'a t
val fold : (key -> 'a -> 'b -> 'b) -> 'a t -> 'b -> 'b
val merge : (key -> 'a option -> 'b option -> 'c option) -> 'a t -> 'b t -> 'c t
val find : env -> key -> 'a t -> 'a
val find_opt : env -> key -> 'a t -> 'a option