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pragma Preelaborate (References);
type Accessor (Data : not null access constant Held_Data) is
limited private;
type Mutator (Data : not null access Held_Data) is
limited private;
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;
function Create
(Constructor : not null access function return Held_Data)
return Immutable_Reference;
-- Create a new held object and return a reference to it
procedure Replace
(Ref : in out Immutable_Reference;
Constructor : not null access function return Held_Data);
-- Replace the object held in Ref with a newly created object
function Create
(Constructor : not null access function return Data_Access)
return Immutable_Reference;
-- Create a new held object and return a reference to it
procedure Replace
(Ref : in out Immutable_Reference;
Constructor : not null access function return Data_Access);
-- Replace the object held in Ref with a newly created object
procedure Reset (Ref : in out Immutable_Reference);
-- Empty Ref
function Is_Empty (Ref : Immutable_Reference) return Boolean;
-- Check whether Ref refers to an actual object
function "=" (Left, Right : Immutable_Reference) return Boolean;
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private
type Counter is new Natural;
type Counter_Access is access Counter;
for Counter_Access'Storage_Pool use Counter_Pool;
type Data_Access is access Held_Data;
for Data_Access'Storage_Pool use Data_Pool;
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