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13.7.2 The Package System.Address_To_Access_Conversions

Static Semantics

The following language-defined generic library package exists:

   
       generic
           type Object(<>) is limited private;
       package System.Address_To_Access_Conversions is
          pragma Preelaborate(Address_To_Access_Conversions);

          type Object_Pointer is access all Object;
          function To_Pointer(Value : Address) return Object_Pointer;
          function To_Address(Value : Object_Pointer) return Address;

          pragma Convention(Intrinsic, To_Pointer);
          pragma Convention(Intrinsic, To_Address);
       end System.Address_To_Access_Conversions;

The To_Pointer and To_Address subprograms convert back and forth between values of types Object_Pointer and Address. To_Pointer(X'Address) is equal to X'Unchecked_Access for any X that allows Unchecked_Access. To_Pointer(Null_Address) returns null. For other addresses, the behavior is unspecified. To_Address(null) returns Null_Address (for null of the appropriate type). To_Address(Y), where Y /= null, returns Y.all'Address.

Implementation Permissions

An implementation may place restrictions on instantiations of Address_To_Access_Conversions.

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