Re: abstract sub programs overriding

[Hyman Rosen <hyrosen@mail.com>]

Dmitry A. Kazakov wrote:
> If that would be true, no C++ library would have Init() in each and
> other class.

As you might already suspect, there is no paucity of poorly designed
C++ code, OO and otherwise. There is also a good deal of C++ that was
written for exception handling disabled, and used Init methods as a
way of detecting failure of construction.

> But they cannot do it, when dispaching methods need to be called as a
> part of base specific object construction.

Correct. This makes the chicken-and-egg problem visible to the programmer,
who must then code a workaround. This is C++ helping, not hindering.

> It quite obvious: "To invoke a service from a derived type" is a more
> complicated way to say "to dispatch". But dispatching is possible on
> class-wide objects only.

But the distinction between classwide objects and non-classwide objects
exists only in your universe. In Ada you can always view-convert an object
into its classwide type.