Re: Doubt in using Math library - C / C++ / MFC Discussion Boards

Re: Doubt in using Math library

CPallini7-Mar-08 5:23

CPallini

7-Mar-08 5:23

But possible, Watson!

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

Re: Doubt in using Math library

Rajkumar R7-Mar-08 5:28

Rajkumar R

7-Mar-08 5:28

Watson! who's that rude fellow Big Grin | :-D

Re: Doubt in using Math library

CPallini7-Mar-08 5:38

CPallini

7-Mar-08 5:38

Well, probably is just one of his friends.
Uhm... A very-very-good-friend since he knows about his CP account details.
Oh Yes, he was his best friend.
Now everyone knows that somebody's best friend is just himself, hence... I'm confused Holmes, please explain...
Laugh | :laugh:

Re: Doubt in using Math library

Maxwell Chen7-Mar-08 5:39

Maxwell Chen

7-Mar-08 5:39

Arsène Lupin?! Jig | [Dance]

Maxwell Chen

Re: Doubt in using Math library

Rajkumar R7-Mar-08 5:48

Rajkumar R

7-Mar-08 5:48

ROTFL !!!

So you got him.
Uhm.. congrats Rose | [Rose]

Re: Doubt in using Math library

Rajesh R Subramanian7-Mar-08 5:52

Rajesh R Subramanian

7-Mar-08 5:52

Yet another "A friend of mine..." story. Get a life, mate.

Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.
Codeproject.com: Visual C++ MVP

Re: Doubt in using Math library

Maxwell Chen7-Mar-08 4:27

Maxwell Chen

7-Mar-08 4:27

CPallini wrote:
See here.

The link is broken. It is not an absolute URL.

Maxwell Chen

Re: Doubt in using Math library

CPallini7-Mar-08 4:36

CPallini

7-Mar-08 4:36

You're right but I think it was a CP bug, not mine.
Smile | :)

Re: Doubt in using Math library

Maxwell Chen7-Mar-08 4:59

Maxwell Chen

7-Mar-08 4:59

CPallini wrote:
it was a CP bug

Take the [PermaLink] to open a new window, and copy that new URL. It will solve! Big Grin | :-D

Maxwell Chen

Re: Doubt in using Math library

Rajkumar R7-Mar-08 5:20

Rajkumar R

7-Mar-08 5:20

Maxwell Chen wrote:
and copy that new URL. It will solve!

how's that possible, do you hacked your domain server policy [^]

Big Grin | :-D

Re: Doubt in using Math library

Maxwell Chen7-Mar-08 5:25

Maxwell Chen

7-Mar-08 5:25

Rajkumar R wrote:
how's that possible, do you hacked your domain server policy [^]

I'm home ~~~ Cool | :cool:

Maxwell Chen

Re: Doubt in using Math library

CPallini7-Mar-08 5:21

CPallini

7-Mar-08 5:21

I told you it was a CP issue. Now it's working fine without my intervention.
Big Grin | :-D

Re: Doubt in using Math library

Maxwell Chen7-Mar-08 5:25

Maxwell Chen

7-Mar-08 5:25

CPallini wrote:
I told you it was a CP issue. Now it's working fine without my intervention.

Yes, indeed! Unsure | :~

Maxwell Chen

Window is launched in the Background when the Alt key is down!

hatemtaleb6-Mar-08 22:39

hatemtaleb

6-Mar-08 22:39

Hi,

For some reason, I need to launch an application from my c++ code while holding the Alt key.
the code is really simple:

<br />
char appName[64];<br />
strcpy(appName,"c:\\WINDOWS\\notepad.exe");<br />
ShellExecute(hWnd,"open",appName,NULL,NULL,SW_SHOWNORMAL);<br />

But when executed whith the Alt key down, the application is opened behind the main window Confused | :confused:

Does anyone have any clue fro this ?

I appreciate your help.
Thanks

anti-standard code can compile -- about template class

George_George6-Mar-08 22:37

George_George

6-Mar-08 22:37

Hello everyone,

According to standard, the code should not compile.

http://gcc.gnu.org/onlinedocs/gcc/Name-lookup.html

template <typename T> struct Base {
   int i;
 };

 template <typename T> struct Derived : public Base<T> {
   int get_i() { return i; }
 };

But it can compile without any issues in Visual Studio 2008, without any warnings and even if I select disable language extensions to yes.

Any comments? What is wrong?

thanks in advance,
George

Re: anti-standard code can compile -- about template class

BadKarma6-Mar-08 22:56

BadKarma

6-Mar-08 22:56

George_George wrote:
According to standard, the code should not compile.

What do you mean with standard?
As far as I can tell the snippit looks fine. And i think that the manual is wrong on this one.
They state: In get_i(), i is not used in a dependent context according to me this is wrong since i is without any doubt the Base<T>::i which is known.

This is indeed a strange situation. Confused | :confused:

codito ergo sum

Re: anti-standard code can compile -- about template class

George_George6-Mar-08 23:30

George_George

6-Mar-08 23:30

Thanks BadKarma,

Seems like Visual Studio is wrong. Please look at section 35.19 of,

http://www.parashift.com/c++-faq-lite/templates.html#faq-35.19[^]

1.

I think this line of statement matters, agree?

--------------------
the compiler does not look in dependent base classes (like B<T>) when looking up nondependent names (like f).
--------------------

2.

What disadvantage do we have if the code can compile?

regards,
George

Re: anti-standard code can compile -- about template class

Maxwell Chen6-Mar-08 23:59

Maxwell Chen

6-Mar-08 23:59

I think current versions of VC++ treat this issue in the manner treating non-template name hiding stuff. Such as:

int a = 3;
for(int i = 0, a = 0; i < 2; i++) {
  printf("a = %d \n", a);
}
printf("a = %d \n", a);

Result:

a = 0 // The inner a
a = 3 // The outer a

Maxwell Chen

Re: anti-standard code can compile -- about template class

George_George7-Mar-08 0:22

George_George

7-Mar-08 0:22

Hi Maxwell,

1. I think Visual Studio 2008 provides correct result in the sample you provided. Are there anything wrong?

2. Does your sample have anything related to my question?

regards,
George

Re: anti-standard code can compile -- about template class

Maxwell Chen7-Mar-08 0:31

Maxwell Chen

7-Mar-08 0:31

George_George wrote:
1. I think Visual Studio 2008 provides correct result in the sample you provided. Are there anything wrong?

2. Does your sample have anything related to my question?

1. I haven't found where in the ISO C++:2003 states how this issue should be working.
But, remember?! You posted Stroustrup's words in previous thread.
And that quote matches GCC document's statement.

2. Something about name resolution ...

Maxwell Chen

Re: anti-standard code can compile -- about template class

George_George7-Mar-08 1:22

George_George

7-Mar-08 1:22

Hi Maxwell,

Thanks. What are the all possible outputs do you think the following sample you posted could give us?

http://www.codeproject.com/script/Forums/View.aspx?fid=1647&msg=2456163[^]

regards,
George

Re: anti-standard code can compile -- about template class

BadKarma6-Mar-08 23:59

BadKarma

6-Mar-08 23:59

George_George wrote:
Seems like Visual Studio is wrong. Please look at section 35.19 of,

http://www.parashift.com/c++-faq-lite/templates.html#faq-35.19[^]

1.I think this line of statement matters, agree?

--------------------
the compiler does not look in dependent base classes (like B<t> when looking up nondependent names (like f).
--------------------

This is correct Visual Studio compiles the non-valid code without any troubles

George_George wrote:
2. What disadvantage do we have if the code can compile?

Thats a hard one since Visual Studio compiles and provides the correct solution. Even when there are global variables or function is correctly understand what the programmer wants and does a check the base class first.

This brings us too two other questions one might ask.
1. Can one write code which breaks this rule? Meaning, can on write code that explicit calls the global function instead of the base function?
2. If this is not possible, why does the rule: the compiler does not look in dependent base classes (like B<t> when looking up nondependent names (like f). exist? Is it because older compilers where not smart enough to clear this up?

codito ergo sum

Re: anti-standard code can compile -- about template class

Maxwell Chen7-Mar-08 0:06

Maxwell Chen

7-Mar-08 0:06

The intention Stroustrup and the ISO C++ team defined this seems because they hoped to avoid the "nasty macro-like behaviours" (see George's previous thread).

Maxwell Chen

Re: anti-standard code can compile -- about template class

George_George7-Mar-08 0:24

George_George

7-Mar-08 0:24

Hi Maxwell,

I understand what means "nasty macro-like behaviours", but I do not think "nasty macro-like behaviours" is similar to my sample in original question?

regards,
George

Re: anti-standard code can compile -- about template class

Maxwell Chen7-Mar-08 0:35

Maxwell Chen

7-Mar-08 0:35

George_George wrote:
I understand what means "nasty macro-like behaviours", but I do not think "nasty macro-like behaviours" is similar to my sample in original question?

Your sample in the original question in this thread originated from your previous thread quoting Stroustrup's words. You forgot?! Unsure | :~

Maxwell Chen

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