Re: [HELP] Why is 'Adjust' not called here ???

["Pat Rogers" <progers@classwide.com>]

"Stephen Leake" <stephen.a.leake.1@gsfc.nasa.gov> wrote in message
news:uofj3ucng.fsf@gsfc.nasa.gov...
> > "Didier Pieroux" <dpieroux@pi.be> wrote in message
> > news:3C5FB880.6FD36A12@hotmail.com...
> > > Hello,
> > >
> > > To make it short: why is 'Adjust' not called during initialization by a
> > > aggregate ?
>
> Because the RM says so :). Pat Rogers gave the RM references.
>
> I believe the rationale is that you can only do initialization by
> aggregate in the body of the package defining the type, so you are
> assumed to know what you are doing, and should do the equivalent of
> the Adjust processing while building the aggregate.
>
> Hmm, what I said about "body of the package" is strictly true only for
> limited controlled types. Still, if you have visibility so you can
> build an aggregate, you are presumed to know what you are doing.


The AARM gives the reason, though it is quite "pedestrian":

17.h.1/1 Reason: This is necessary to prevent elaboration problems with deferred
constants of controlled types. Consider:

package P is
   type Dyn_String is private;
   Null_String : constant Dyn_String;
   ...
private
   type Dyn_String is new Ada.Finalization.Controlled with ...
   procedure Finalize(X : in out Dyn_String);
   procedure Adjust(X : in out Dyn_String);

   Null_String : constant Dyn_String :=
      (Ada.Finalization.Controlled with ...);
   ...
end P;

17.h.3/1 When Null_String is elaborated, the bodies of Finalize and Adjust
clearly have not been elaborated. Without this rule, this declaration would
necessarily raise Program_Error (unless the permissions given below are used by
the compiler).