Re: HOWTO use a Factory

From:
"Victor Bazarov" <v.Abazarov@comAcast.net>
Newsgroups:
comp.lang.c++
Date:
Wed, 22 Aug 2007 21:15:17 -0400
Message-ID:
<fain44$g2n$1@news.datemas.de>
Goran wrote:

On Aug 22, 11:52 pm, "Victor Bazarov" <v.Abaza...@comAcast.net> wrote:

Goran wrote:
[...]

Now I know it's bad to throw an exception in a constructor.


No, it's not bad. It's the only way to let the caller know that
construction cannot be completed.


Ok, it's not bad :) but how could i use a try/catch with such a
constructor?

try {
       Example_t myExample("fooBar");
}
// myExample is lost...


Yes, here it's lost. Put all your code inside the 'try' clause.

catch(...) {
       cout << "Exception" << endl;
}

But what else?


Depends.

[...]

The only "elegant" way that comes to mind is to return *a copy* of
some kind of "invalid" or "generic" object that can be inquired
about its own validity and discarded by the caller.


How looks like such an object :) ?


If you meant to ask, "what does such an object look like?", then
I have no idea since it's *your* object, *your* problem domain,
*your* model.

V
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