Re: Constructing an object

[Matthew Heaney <matthewjheaney@earthlink.net>]

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:

> Replace it with:
> 
> type Shape (<>) is private;

Yes, but now the type is indefinite, which means you can't declare it as
a component of a composite type.  (This is no different from C++, when
you hide the default ctor.)

The easiest thing is just to default initialize the component(s), and
don't bother declaring the type as indefinite. If you still want to
force some post-declaration initialization, then you do something like:

  type Color_Base is (Uninitialized, Red, Black);
  subtype Color is Color_Base range Red .. Black;

  type Shape is tagged private;

  procedure Set_Color (S : in out Shape; C : Color);
...
private
  type Shape is tagged record
     C : Color_Base := Uninitialized;
  end record;
...
end Shapes;

But again, that would only be necessary if you don't have a sensible
default.  In this particular case, you probably don't need to bother;
just pick on of the colors as the default.