Re: Translating C++ class types into Ada tagged types?

[Gerd <GerdM.O@t-online.de>]

tmo...@acm.org schrieb:
> You can force the user to give an initial age by
>
>  package Animals is
>     type Cat(Initial_Age : Positive) is tagged private;
>  ...
>     type Cat(Initial_Age : Positive) is tagged record
>        Age : Positive := Initial_Age;
>     end record;
>  ...
>     Frisky : Animals.Cat(Initial_Age => 0);
> If you want the initialization to be significantly more complicated
> than that, you can make type Cat controlled, with Initialize and
> Finalize procedures.


Is this dot notation a new feature of Ada 2005? As far as I know (my
own trials, long ago) it is not possible with Ada95.
     Frisky : Animals.Cat(Initial_Age => 0);


Lets assume the following code (maybe not syntactically correct),
would it work this way, or how would it be done?

package Vehicle is
  type Car is tagged record
    NrWheels : Positive := 4;
  end record;

 function Wheels (c : Car'Class) return Positive;
end Vehicle;

with Vehicle
package TransportCar is
  type BigCar is new Car with
    record
       Seats : Positive;
    end record;

  function Seats (bc : BigCar) return Positive;

end TransportCar;

...

with Car;
with TransportCar;

MyCar : TransportCar;

...

nrseat := MyCar.Seats;
nswheels := MyCar.Wheels;

Does the compiler know where the functions come from, or must I write
it like in

nrwheels := Car.Wheels (MyCar);
nrseats := TransportCar.Seat(MyCar)