Re: Free'ing dynamic abstract tagged types..

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On 21 Sep 2006 14:08:04 -0700, ldb wrote:

> Ok, so I have this abstract tagged type called Person (for the sake of
> discussion), and I have an Access_Person (which is access all
> people'class).
> 
> I have some derived types, like Man and Child, with their own added
> fields. And I have defined Access_Man, Access_Child, as normal accesses
> to these types.

That usually were a bad idea, because it creates a parallel types
hierarchy:

Person <-- Man
Specific_Access_Person <-- Specific_Access_Man

Maintaining both is an unnecessary burden.

Note that you can allocate Man having Access_Person as the target. Usual
pattern is:

   Man_Ptr : Access_Person := new Man;
      -- OK, we want to access some fields of Man after having
      -- created it, so:
   declare
      Object : Man'Class renames Man'Class (Man_Ptr.all);
   begin
      -- Do with Object what you have to with Man. Object
      -- is not new, it is a Man'Class view of the thing pointed
      -- by Man_Ptr.
      ...
   end;

> I want to free an Access_Person that was dynamically allocated.
> ap : Access_Person;
> begin
> ap := Access_Person(new Man);
> free(ap);
> ...

Others have answered this.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de