val initial_counters: counters
-val count_item: (counters -> 'a) -> counters -> Meta.item -> 'a
+val count_unit: (counters -> 'a) -> counters -> Meta.unit -> 'a
val print_counters: (unit -> 'a) -> counters -> 'a
-val pp_item: (unit -> 'a) -> Format.formatter -> Meta.item -> 'a
+val pp_unit: (unit -> 'a) -> Format.formatter -> Meta.unit -> 'a