module type THREAD_LOCAL_STATE = sig .. end
sig
end
type 'a t
'a
type 'a key
val new_key : unit -> 'a key
unit -> 'a key
val get : 'a key -> 'a option
'a key -> 'a option
val with_value : 'a key -> 'a option -> (unit -> 'b t) -> 'b t
'a key -> 'a option -> (unit -> 'b t) -> 'b t