Fundamental question about visibility

[Casper Bang]

Re: Fundamental question about visibility

Adding custom constructors for passing of desired objects works but is not
exactly an elegant solution.
I solved it with the suspected GetParent call:

((<DerivedClass >)GetParent()). <MemberName>
^
Returns base class!

....but I had to cast to the overidden class and NOT rely on C++ to know
this! I would've thought GetParent pointed to the new class and not the old
but maybe this is simply a MFC specific twist. One more lesson learned!

Thanks for the feedback,
Casper

----------

"WW" <wolof@freemail .hu> wrote in message
news:bkqp6e$c2n $1@phys-news1.kolumbus. fi...[color=blue]
> WW wrote:
> [SNIP]
> Update
>[color=green]
> > // Overide the CEdit class so we can capture CTRL + ENTER events
> > class CModifiedEdit : public CEdit
> > {
> > CMainWindow *parent;[/color]
>
> Here I hope a *lot* that CEdit does have a virtual destructor. In our[/color]
case[color=blue]
> it does not really matter (there is no descruction for a pointer and[/color]
Windows[color=blue]
> will release the memory properly) but according to Standard C++ it is[/color]
better[color=blue]
> be there. (Also in your code CMainWindow will always destroy[/color]
CModifiedEdit[color=blue]
> as CModifiedEdit, but later if you go dynamic about the GUI it might not[/color]
be[color=blue]
> the case.)
>[color=green]
> > public:
> > CModifiedEdit(C MainWindow *mamma) : parent(mamma) { ; }
> > afx_msg void OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags);
> > };[/color]
> [SNIP]
> --
> WW aka Attila
>
>[/color]

[WW]

Re: Fundamental question about visibility

Casper Bang wrote:[color=blue]
> Adding custom constructors for passing of desired objects works but
> is not exactly an elegant solution.
> I solved it with the suspected GetParent call:
>
> ((<DerivedClass >)GetParent()). <MemberName>
> ^
> Returns base class!
>
> ...but I had to cast to the overidden class and NOT rely on C++ to
> know this! I would've thought GetParent pointed to the new class and
> not the old but maybe this is simply a MFC specific twist. One more
> lesson learned![/color]

Don't top post! I will not suggest using templates to someone possibly
using VC++ 6.0.

--
WW aka Attila

[jeffc]

Re: Fundamental question about visibility


"WW" <wolof@freemail .hu> wrote in message
news:bksfn7$bei $1@phys-news1.kolumbus. fi...[color=blue][color=green]
> >
> > I'll let you read about it "The C++ Programming Language" by Bjarne
> > Stroustrup. In the meantime, if you can possibly be any more
> > pedantic, please do. It would amaze me.[/color]
>
> You mean the quote that some people, sometimes may call virtual member
> functions methods? A very widely accepted definition. See the original
> post of this thread.[/color]

I don't need to look past the post that said "There are no methods in C++."
[color=blue]
> If you choose to use a vague and confusing term (with no exact definition)
> by all means do it. But then do not wonder if people think you are not[/color]
here[color=blue]
> to help.[/color]

Riiiiiiight, Mr. Pedant. No one had a problem with the OP's question except
you. Now, who wasn't here to help, but to display his dictionary knowledge
of the C++ language?

[Shane Beasley]

Re: Fundamental question about visibility

"WW" <wolof@freemail .hu> wrote in message news:<bksbbe$se 3$1@phys-news1.kolumbus. fi>...
[color=blue]
> Please, if you *know* what method means in the realm of the C++ language...
> by all means, post it here![/color]

<http://www.nightflight .com/foldoc-bin/foldoc.cgi?meth od>

"The name given in Smalltalk and other object-oriented languages to a
procedure or routine associated with one or more classes. An object of
a certain class knows how to perform actions, e.g. printing itself or
creating a new instance of itself, rather than the function (e.g.
printing) knowing how to handle different types of object."

Sounds like a virtual function to me. Actually, FOLDOC also mentions
the concept of a "class method" -- that's a static member function, of
course.

Given this, one might say that it is incorrect to use "method" to
describe a non-virtual member function, although I have yet to find
any such use to be confusing or misleading, so I don't even bother
bringing that up. I might almost mention it if a non-member function
were called a method, though.

- Shane

[WW]

Re: Fundamental question about visibility

jeffc wrote:[color=blue]
> "WW" <wolof@freemail .hu> wrote in message
> news:bksfn7$bei $1@phys-news1.kolumbus. fi...[color=green][color=darkred]
>>>
>>> I'll let you read about it "The C++ Programming Language" by Bjarne
>>> Stroustrup. In the meantime, if you can possibly be any more
>>> pedantic, please do. It would amaze me.[/color]
>>
>> You mean the quote that some people, sometimes may call virtual
>> member functions methods? A very widely accepted definition. See
>> the original post of this thread.[/color]
>
> I don't need to look past the post that said "There are no methods in
> C++."[/color]

Again: you refer to TC++PL for what method means. That says: *some* call
virtual member functions methods. My proof: look at what the OPs original
post and realise that he was *not* using method in the sense Mr. Stroustrup
says *some* (apparently other) people do.

Stop trolling.
[color=blue][color=green]
>> If you choose to use a vague and confusing term (with no exact
>> definition) by all means do it. But then do not wonder if people
>> think you are not here to help.[/color]
>
> Riiiiiiight, Mr. Pedant.[/color]

Please read my name Mr. Infantile. It is not Mr. Pedant. Stop trolling.
[color=blue]
> No one had a problem with the OP's question
> except you.[/color]

I had no problem with the question. I have answered it. Stop trolling.
[color=blue]
> Now, who wasn't here to help, but to display his
> dictionary knowledge of the C++ language?[/color]

And what are you here for? To get into every thread and try to attack me
because you think it is cool? Stop trolling. You help none, on the
contrary.

BTW NICE SNIPPING! How come you have snipped out that Steve Dewhurst's book
(C++ Gothcas) exactly my advice: do not use the word method in C++
discussions? Ah. Because that was showing that all you do is troll to
practice your ego.

The OP had no problem with my advice. The OP was (instead of you) showing
no attitude and has got answer to his questions. So why don't you get lost
for ever? It is clear you do not have the mental capacity to help, so you
troll. No need for that. Find another place where you can scream and
wallow on the ground to get into the center of attention. Stop trolling.

--
WW aka Attila

[WW]

Re: Fundamental question about visibility

Shane Beasley wrote:[color=blue]
> "WW" <wolof@freemail .hu> wrote in message
> news:<bksbbe$se 3$1@phys-news1.kolumbus. fi>...
>[color=green]
>> Please, if you *know* what method means in the realm of the C++
>> language...
>> by all means, post it here![/color]
>
> <http://www.nightflight .com/foldoc-bin/foldoc.cgi?meth od>
>
> "The name given in Smalltalk and other object-oriented languages to a
> procedure or routine associated with one or more classes. An object of
> a certain class knows how to perform actions, e.g. printing itself or
> creating a new instance of itself, rather than the function (e.g.
> printing) knowing how to handle different types of object."
>
> Sounds like a virtual function to me. Actually, FOLDOC also mentions
> the concept of a "class method" -- that's a static member function, of
> course.
>
> Given this, one might say that it is incorrect to use "method" to
> describe a non-virtual member function, although I have yet to find
> any such use to be confusing or misleading, so I don't even bother
> bringing that up. I might almost mention it if a non-member function
> were called a method, though.[/color]

Method has no definition in a C++ discussion. It can only cause
imprecision, confusion and misunderstandin g.

--
WW aka Attila

[Gavin Deane]

Re: Fundamental question about visibility

"jeffc" <nobody@nowhere .com> wrote in message news:<3f71e1d0_ 4@news1.prserv. net>...[color=blue]
> "WW" <wolof@freemail .hu> wrote in message
> news:bksfn7$bei $1@phys-news1.kolumbus. fi...[color=green]
> > If you choose to use a vague and confusing term (with no exact definition)
> > by all means do it. But then do not wonder if people think you are not[/color]
> here[color=green]
> > to help.[/color]
>
> Riiiiiiight, Mr. Pedant. No one had a problem with the OP's question except
> you. Now, who wasn't here to help, but to display his dictionary knowledge
> of the C++ language?[/color]

How do you know how many other people also had an objection to the use
of 'method' but elected not to mention it after WW had already brought
it up?

And how does the exchange between the OP and WW which ended with the
OP's problem solved lead you to conclude that WW wasn't helping?

[Attila Feher]

Re: Fundamental question about visibility

Gavin Deane wrote:
[SNIP][color=blue][color=green]
>> Riiiiiiight, Mr. Pedant. No one had a problem with the OP's
>> question except you. Now, who wasn't here to help, but to display
>> his dictionary knowledge of the C++ language?[/color]
>
> How do you know how many other people also had an objection to the use
> of 'method' but elected not to mention it after WW had already brought
> it up?
>
> And how does the exchange between the OP and WW which ended with the
> OP's problem solved lead you to conclude that WW wasn't helping?[/color]

He does not conclude. He prejudges.

--
Attila aka WW

[jeffc]

Re: Fundamental question about visibility


"WW" <wolof@freemail .hu> wrote in message
news:bktoeu$58i $1@phys-news1.kolumbus. fi...[color=blue]
>
> BTW NICE SNIPPING! How come you have snipped out that Steve Dewhurst's[/color]
book[color=blue]
> (C++ Gothcas) exactly my advice: do not use the word method in C++
> discussions? Ah. Because that was showing that all you do is troll to
> practice your ego.[/color]

Because you're a pedant.

[jeffc]

Re: Fundamental question about visibility


"Gavin Deane" <deane_gavin@ho tmail.com> wrote in message
news:6d8002d0.0 309250324.4205c b1@posting.goog le.com...[color=blue]
>
> How do you know how many other people also had an objection to the use
> of 'method' but elected not to mention it after WW had already brought
> it up?[/color]

I'd argue with all the pedants. Anyone who wastes a post telling someone
else that "method is not part of the C++ standard language! nyah nyah!" has
a stick way too far up their rear.

[jeffc]

Re: Fundamental question about visibility


"WW" <wolof@freemail .hu> wrote in message
news:bktoi1$591 $1@phys-news1.kolumbus. fi...[color=blue]
>
> Method has no definition in a C++ discussion. It can only cause
> imprecision, confusion and misunderstandin g.[/color]

Yeah, right.

[jeffc]

Re: Fundamental question about visibility


"Gavin Deane" <deane_gavin@ho tmail.com> wrote in message
news:6d8002d0.0 309250324.4205c b1@posting.goog le.com...[color=blue]
> And how does the exchange between the OP and WW which ended with the
> OP's problem solved lead you to conclude that WW wasn't helping?[/color]

The part about the method was completely unhelpful. He was just saying it
to show off his book knowledge of detail unrelated to the question, so he
can appear authoritative, toe the party line, be part of the cool C++ geek
crowd, and waste space in the newsgroup. People like that are only
motivated partially by helping people. Terms like method are completely
valid when discussing C++ design and code, regardless of whether the word
appears in the C++ keyword list, or even the official standard. Just like
base class, parent class, and superclass can be used interchangably, even
though you won't find them in the language. Unlike some people, I'm not
sitting here with a steel rod up my butt waiting for the next time someone
uses the term superclass so I can pounce on them for using a word that
doesn't exist in the language.

[Noah Roberts]

Re: Fundamental question about visibility

WW wrote:[color=blue]
> jeffc wrote:
>[color=green]
>>"WW" <wolof@freemail .hu> wrote in message
>>news:bkqkn3$5 ld$1@phys-news1.kolumbus. fi...
>>[color=darkred]
>>>Casper Bang wrote:
>>>
>>>>My question is fundamental I beleive but it has been teasing me for
>>>>a while:
>>>>
>>>>I have two classes in my app. The first class is instantiated as a
>>>>member of my second class. Within this first class, a method (event)
>>>>needs to be able to invoke methods of the second class.
>>>
>>>There are no methods in C++. There are member functions.[/color]
>>
>>Oh brother. <warning>Pedant Police<warning>[/color]
>
>
> Please, if you *know* what method means in the realm of the C++ language...
> by all means, post it here!
>[/color]

Methods are actions you may request that an object carry out. You
invoke 'methods' by passing 'messages'; methods are implementations of
messages. This is basic OO terminology that you learn in any
introductory text.

The problem with C++ is that when you pass a message to an object it is
not necissarily the one that carries out the action even if it has
overridden its parent's methods. This is only guaranteed if the method
is declaired virtual in *all* parents. I suppose this is why some
people would consider only virtual 'functions' to be methods and why
others would object to a "member function" being called a method at all.
This is also one of the reasons I find C++ does not quite apply the OO
paradigm (which can be a strength at times).

There is also the fact that all C++ "member functions" eventually get
altered to in fact be functions that accept class structs as arguments.
I myself don't believe this should have an impact on our terminology
as it is an implementation detail that the programmer never really sees.
In other OO languages the term method is used and they also get
altered by the compiler to have a more function like signature. For
example Objective-C works this way (many even just preprocess into C)
but we use OO terms not procedural terms.

In my opinion the *only* reason to call a method "member function" is
because it is what C++ programmer terminology uses; and of course
because there are some who will pretend not to know what you mean, go
off on some rant, and may never answer the question. The term
"function" is really not an OO concept and, in my opinion, it is a
mistake to use it as such.

NR

[jeffc]

Re: Fundamental question about visibility


"Noah Roberts" <nroberts@donte mailme.com> wrote in message
news:3F73070B.1 0000@dontemailm e.com...[color=blue]
>
> Methods are actions you may request that an object carry out. You
> invoke 'methods' by passing 'messages'; methods are implementations of
> messages. This is basic OO terminology that you learn in any
> introductory text.
>
> The problem with C++ is that when you pass a message to an object it is
> not necissarily the one that carries out the action even if it has
> overridden its parent's methods. This is only guaranteed if the method
> is declaired virtual in *all* parents. I suppose this is why some
> people would consider only virtual 'functions' to be methods and why
> others would object to a "member function" being called a method at all.
> This is also one of the reasons I find C++ does not quite apply the OO
> paradigm (which can be a strength at times).
>
> There is also the fact that all C++ "member functions" eventually get
> altered to in fact be functions that accept class structs as arguments.
> I myself don't believe this should have an impact on our terminology
> as it is an implementation detail that the programmer never really sees.
> In other OO languages the term method is used and they also get
> altered by the compiler to have a more function like signature. For
> example Objective-C works this way (many even just preprocess into C)
> but we use OO terms not procedural terms.
>
> In my opinion the *only* reason to call a method "member function" is
> because it is what C++ programmer terminology uses; and of course
> because there are some who will pretend not to know what you mean, go
> off on some rant, and may never answer the question.[/color]

Now that is the voice of reason. Having said all that, it's pretty clear
why we don't have to post a whole page like this just because someone in
this newsgroup uses the term "method".

[WW]

Re: Fundamental question about visibility

jeffc wrote:[color=blue]
> "WW" <wolof@freemail .hu> wrote in message
> news:bktoeu$58i $1@phys-news1.kolumbus. fi...[color=green]
>>
>> BTW NICE SNIPPING! How come you have snipped out that Steve
>> Dewhurst's book (C++ Gothcas) exactly my advice: do not use the word
>> method in C++ discussions? Ah. Because that was showing that all
>> you do is troll to practice your ego.[/color]
>
> Because you're a pedant.[/color]

Stop trolling.

--
WW aka Attila