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Newsgroups: comp.lang.ada
Date: Wed, 28 Jun 2017 07:05:59 -0700 (PDT)
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Subject: Re: Ada Annoyances
From: AdaMagica <christ-usch.grein@t-online.de>
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Xref: news.eternal-september.org comp.lang.ada:47160
Date: 2017-06-28T07:05:59-07:00
List-Id: <comp.lang.ada>

Am Mittwoch, 28. Juni 2017 15:16:00 UTC+2 schrieb Maciej Sobczak:
> > The following uses *functions* instead (which behave more like C++'s co=
nstructors).
>=20
> No, C++ constructors have nothing to do with functions. They do not retur=
n anything and in particular within the class hierarchy, where the construc=
tion process has multiple stages and constructors operate on partial views =
on the target object, it is clear that they have little analogies with regu=
lar functions.

That's all correct. My point was that your Initialize procedures were in no=
 way comparable to C++ constructors, so your translation of C++ to Ada was =
questionable. The Ada functions' distance to constructors is far less. As I=
 said in the comments of my example, there are no true constructors in Ada.

> Still:
>
> > This program works correctly just like the C++ version.
> [...]
>
> I like your example. It demonstrates that factory functions are better su=
ited to implement the design intent that we have discussed.

That was my intent. With package Ada.Finalization, one has to be very caref=
ul to avoid such re-dispatching as in your example. When I created my examp=
le, I first used procedures like you did - and fell into the same trap.