Natools

   Counter_Pool : in out System.Storage_Pools.Root_Storage_Pool'Class;
   Data_Pool : in out System.Storage_Pools.Root_Storage_Pool'Class;

package Natools.References is
   pragma Preelaborate (References);

   type Accessor (Data : not null access constant Held_Data) is
     limited private;
     limited private with Implicit_Dereference => Data;
   type Mutator (Data : not null access Held_Data) is
     limited private;
     limited private with Implicit_Dereference => Data;

   type Data_Access is access Held_Data;
   for Data_Access'Storage_Pool use Data_Pool;


   type Immutable_Reference is new Ada.Finalization.Controlled with private;
   pragma Preelaborable_Initialization (Immutable_Reference);