Re: Q: Ada.Unchecked_Deallocation

[bobduff@world.std.com (Robert A Duff)]

In article <ws9zq4un5ni.fsf@schonberg.cs.nyu.edu>,
Laurent Guerby <guerby@gnat.com> wrote:
>   type KLUNK_WITH_EMPTY_FINALIZE is new KLUNK with null record;
>   procedure Finalize (Obj : KLUNK) is
>   begin null; end Finalize;
>
>   And instead of applying the pragma, you declare objects of this new type.
>A smart compiler can optimize away calls to such a Finalize subprogram.

This would have to be a link-time optimization.

Instead, do it the other way around: Define the no-finalize version
first, and then derive the finalized version from that.  Then, the
compiler *can* tell (at compile time) that the first type has null
Finalize, since it doesn't override the known-null version inherited
from type Controlled.

Either way, you have to be careful, though.  You can't declare nested
objects of the no-finalize type, or you'll get a storage leak.  And what
if it's in a generic package, which is *sometimes* instantiated in a
nested place?

- Bob