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13.7.2 The Package System.Address_To_Access_Conversions

Static Semantics

1
The following language-defined generic library package exists: 
2
generic
    type Object(<>) is limited private;
package System.Address_To_Access_Conversions is
   pragma Preelaborate(Address_To_Access_Conversions);
3
   type Object_Pointer is access all Object;
   function To_Pointer(Value : Address) return Object_Pointer;
   function To_Address(Value : Object_Pointer) return Address;
4
   pragma Convention(Intrinsic, To_Pointer);
   pragma Convention(Intrinsic, To_Address);
end System.Address_To_Access_Conversions;
5/2
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. To_Address(Y), where Y /= null, returns Y.all'Address. 

Implementation Permissions

6
An implementation may place restrictions on instantiations of Address_To_Access_Conversions. 

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