Re: Obtaining access to protected object

[george.priv@gmail.com]

On Jul 8, 4:41 pm, Maciej Sobczak <see.my.homep...@gmail.com> wrote:
> Consider 9.4-21/2:
>
> "Within the declaration or body of a protected unit other than in an
> access_definition, the name of the protected unit denotes the current
> instance of the unit"
>
> I understand that this allows me to obtain the access to the current
> object (the "this" access) of the protected object.
> Let's try:
>
>    protected type P is
>       procedure Foo;
>    end P;
>
>    protected body P is
>       procedure Foo is
>          Ptr : access P;   -- P denotes the type P
>       begin
>          Ptr := P'Access;    -- here P denotes the "this" instance of
> P
>       end;
>    end P;
>
> This is what GNAT has to say about it: ""Access" attribute cannot be
> applied to type".
> As far as I understand, this is in conflict with the AARM paragraph
> mentioned above.
>
> Am I doing something wrong or is it a compiler bug?
>
> --
> Maciej Sobczak *www.msobczak.com*www.inspirel.com

The instance may not be aliased, and type itself is not enough to
determine that at compile time.

You can reference the protected type "this" instance though:

   protected type Xt is
      procedure Foo;
   end Xt;

   procedure Call_Foo (A : in out Xt);

   protected body Xt is

      procedure Foo is
      begin
         Call_Foo (Xt);
      end;

   end Xt;