Re: Discriminant and type extensions

[Adam Beneschan <adam@irvine.com>]

On Oct 5, 3:34 pm, Yannick Duchêne Hibou57 <yannick_duch...@yahoo.fr>
wrote:
> Re- Not legal, the compiler don't want this

Referring to the example where you removed the genericity:

If you put this on *both* the private and full declarations of
Extension_Type:

  type Extension_Type (Discriminant : Natural) is
     new P1.T_Type (Discriminant => Discriminant)

then take the (Discriminant => Discriminant) off the *private*
extension declaration.  I.e.:

  type Extension_Type (Discriminant : Natural) is
     new P1.T_Type
     with private;

But leave it on the full declaration:

  type Extension_Type (Discriminant : Natural) is
     new P1.T_Type (Discriminant => Discriminant)
     with null record;

See if that works.

The reason has to do with a rule about statically matching
constraints.  See AARM 7.3(13.e), at http://www.adaic.org/standards/05aarm/html/AA-7-3.html
-- look for paragraph 13.e.

                                    -- Adam