Hi,
I didn't know how else to express myself in the subject line, but what
I want to know is this: <b>I have a class A, so what do I have to do
to ensure that no one can derive from it?</b>
Saumya
11  1611 
Saumya wrote: Hi,
I didn't know how else to express myself in the subject line, but what
I want to know is this: <b>I have a class A, so what do I have to do
to ensure that no one can derive from it?</b>
Saumya
Why do you want to do this? Explaining what you want to achieve with this
behaviour would help to find a meaningful solution.
--
To get my real email adress, remove the two onkas
--
Dipl.-Inform. Hendrik Belitz
Central Institute of Electronics
Research Center Juelich
As Christian already posted, there are at least three ways to do so. But: There's no way in C++ as simple as
"final" in Java:
The first approach needs additional static member functions, the second comment-only approach only
works iff the user cooperates, and the third one needs a "friend" declaration in a virtual base class, which
isn't nice either. And in my opinion "final"izat ion imposes a large limitation to the usage of you class.
Therefore think twice, please, whether you can't change your design such not to need to make
your class behave like "final" any more.
Cheers,
Philipp.
"Saumya" <sa**********@y ahoo.com> wrote in message news:e9******** *************** ***@posting.goo gle.com... Hi,
I didn't know how else to express myself in the subject line, but what
I want to know is this: <b>I have a class A, so what do I have to do
to ensure that no one can derive from it?</b>
Saumya
"Philipp Bachmann
As Christian already posted, there are at least three ways to do so. But: There's no way in C++ as simple as
"final" in Java:
The first approach needs additional static member functions, the second comment-only approach only
works iff the user cooperates, and the third one needs a "friend" declaration in a virtual base class, which
isn't nice either. And in my opinion "final"izat ion imposes a large limitation to the usage of you class.
Hmm. So it seems I am not alone.
All always wondered: Why would one want to impose such a 'finalization' to a class. What
is the purpose of doing so?
--
Karl Heinz Buchegger kb******@gascad .at
I think the only good reason is to force users of the class to aggregate
instead of inherit.
Consider a socket implementation, normally a socket class gives no meaning
to inherit from, it is like inheriting from std::iostream..
Sure there maybe where it could make sence, but for common use it doesn't..
Jesper
"Karl Heinz Buchegger" <kb******@gasca d.at> wrote in message
news:40******** *******@gascad. at... "Philipp Bachmann
As Christian already posted, there are at least three ways to do so.
But: There's no way in C++ as simple as "final" in Java:
The first approach needs additional static member functions, the second
comment-only approach only works iff the user cooperates, and the third one needs a "friend"
declaration in a virtual base class, which isn't nice either. And in my opinion "final"izat ion imposes a large
limitation to the usage of you class.
Hmm. So it seems I am not alone.
All always wondered: Why would one want to impose such a 'finalization' to
a class. What is the purpose of doing so?
--
Karl Heinz Buchegger
kb******@gascad .at
Not a very technical reason pal, but it just struck me while I was
learning Java and encountered the "final" keyword there.
Also, it struck me that what if I was asked this question in some
technical interview ;-)
Saumya <sa**********@y ahoo.com> spoke thus: Not a very technical reason pal, but it just struck me while I was
learning Java and encountered the "final" keyword there.
http://www.parashift.com/c++-faq-lit....html#faq-23.8
Also, it struck me that what if I was asked this question in some
technical interview ;-)
Just memorize the above URL? ;)
--
Christopher Benson-Manica | I *should* know what I'm talking about - if I
ataru(at)cybers pace.org | don't, I need to know. Flames welcome.
I am really wondering who needs such a thing ...
Razvan
"Christophe r Benson-Manica" <at***@nospam.c yberspace.org> schrieb im
Newsbeitrag news:c1******** **@chessie.cirr .com... Saumya <sa**********@y ahoo.com> spoke thus:
Not a very technical reason pal, but it just struck me while I was
learning Java and encountered the "final" keyword there.
http://www.parashift.com/c++-faq-lit....html#faq-23.8
Also, it struck me that what if I was asked this question in some
technical interview ;-)
Just memorize the above URL? ;)
--
Christopher Benson-Manica | I *should* know what I'm talking about - if I
ataru(at)cybers pace.org | don't, I need to know. Flames welcome.
> Hmm. So it seems I am not alone. All always wondered: Why would one want to impose such a 'finalization' to a class. What
is the purpose of doing so?
No you aren't alone. 'finalization' seems almost equivalent to asking:
"How can I prevent someone from reusing my code?"
The idiom seems to fit well in Java, however. I always do feel like
I'm wearing a straight-jacket when I code in Java. So heck, why not
'finalize' the classes to prevent there reuse. After all, you never
know when someone (possibly even yourself) might try to reuse it
without your permission possibly messing up the aesthetic symmetry
your 'pre-planned' class hierarchy. Shame on them.
"I have opinions, strong opinions, but, I don't always agree with
them."
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