Re: C++ templates - C / C++ / MFC Discussion Boards

Re: template specialization

Nelek12-Sep-07 4:32

Nelek

12-Sep-07 4:32

And what about ...?

template < class A, class B >
class CMyClass < A, B >::foo (class A1)
{
if (A1->IsKindOf (RUNTIME_CLASS ( A )))
//do something
else
//do something different
}

EDIT: I actually am not sure if I understand the question right. A bit more info would be nice.

Greetings.

--------
M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?

Re: template specialization

Russell^'12-Sep-07 5:15

Russell^'

12-Sep-07 5:15

sure...in that way it could work, but I prefere to use a simple "template specialization" it works well if all typenames must be specialized. But this is the first time that I have to specialize only a typename, so I I'm trying to find the correct sintax. Cry | :((

thanks for your time Big Grin | :-D

Russell

Re: template specialization

Russell^'12-Sep-07 4:35

Russell^'

12-Sep-07 4:35

I'm trying... I'll tell you the results tomorrow. Wink | ;)

thanks

Russell

C++ templates

minkowski12-Sep-07 2:48

minkowski

12-Sep-07 2:48

Hi,

I have found out (the hard way!) that you can't have a .cpp file with your function definitions if you are using a template class. All your function definitions must be in the .h file. Why is this?

Thanks for any info.

Re: C++ templates

Jonathan [Darka]12-Sep-07 2:49

Jonathan [Darka]

12-Sep-07 2:49

You can put the code in a C++ file, you just need to change how you define your templates.

I would not recommend that though, justuse a header file it's much easier.

regards,

Jonathan Wilkes
Darka[Xanya.net]

Re: C++ templates

minkowski12-Sep-07 3:09

minkowski

12-Sep-07 3:09

Hi,

Thanks for that, but do you know why the C++ compilier objects to having function definitions in the .cpp ?

Thanks.

Re: C++ templates

Cedric Moonen12-Sep-07 3:16

Cedric Moonen

12-Sep-07 3:16

AFAIK it is because template code is generated by your compiler. It means that when you have a template instantiation (something like list<float> ) your compiler will generate code corresponding to this template type. To be able to generate the code, it needs the complete function implementation.

Cédric Moonen
Software developer

Charting control [v1.2]

Re: C++ templates

jhwurmbach12-Sep-07 3:19

jhwurmbach

12-Sep-07 3:19

You do *not* have to have definitions in th ecpp.
You do this to (partially) separate interface and implementation.

With templates, every instantiation (for type A, type B etc) creates a new, distinct type: vector<A> is different from vector<B>.
And for this instantiation, the compiler needs the complete definition of the template. Therefore it is easiest to put the template in the header, to have it ready when you need it.

Though I speak with the tongues of men and of angels, and have not money, I am become as a sounding brass, or a tinkling cymbal.
George Orwell, "Keep the Aspidistra Flying", Opening words

Re: C++ templates

Russell^'12-Sep-07 3:18

Russell^'

12-Sep-07 3:18

Yes, all in the .h file.
Only specializations must be putted in the .cpp file (declaraion, of course, in the .h file).

minkowski wrote:
Why is this?

I think that this has only a reason related to how the compiler works to elaborates the templates.

I hope that this isn't a problem for you. Unsure | :~

Russell

Re: C++ templates

Nemanja Trifunovic12-Sep-07 5:00

Nemanja Trifunovic

12-Sep-07 5:00

minkowski wrote:
Why is this?

See here[^]

Programming Blog
utf8-cpp

Is it possible to hide a column of a Clist control?

Md. Ali Naser Khan12-Sep-07 2:40

Md. Ali Naser Khan

12-Sep-07 2:40

I have a list control of CListCtrl type and it has 3 columns. I want to hide the first column(of course, it will work internally). Is it possible?

Re: Is it possible to hide a column of a Clist control?

David Crow12-Sep-07 2:52

David Crow

12-Sep-07 2:52

Just out of curiosity, why do you need/want to do this?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Is it possible to hide a column of a Clist control?

Nishad S12-Sep-07 3:00

Nishad S

12-Sep-07 3:00

Cant you make it of zero width?

- NS -

Re: Is it possible to hide a column of a Clist control?

Manfred Staiger12-Sep-07 3:02

Manfred Staiger

12-Sep-07 3:02

How about setting the width of that column to zero?

Re: Is it possible to hide a column of a Clist control?

Hamid_RT12-Sep-07 6:48

Hamid_RT

12-Sep-07 6:48

Can you more explain why you need to do it?

Difference between debug and release builds

bhogavalli suresh12-Sep-07 2:10

bhogavalli suresh

12-Sep-07 2:10

plz tel the Difference between debug and release builds.

Re: Difference between debug and release builds

chandu00412-Sep-07 2:19

chandu004

12-Sep-07 2:19

the basic difference is the debug information will be embedded in the exe in debug build which is not possible in release build.is it suficient or are u looking for anything else.

Re: Difference between debug and release builds

Nelek12-Sep-07 2:39

Nelek

12-Sep-07 2:39

Another difference is that debug mode can maybe work perfectly, but same code in release may crush in hundreds of places.

Debug assumes some things when nothing is said, or automatically correct some errors of intialization.
Release executes ONLY what the programmer has written. If it is not correctly written will crush.

Greetings.

--------
M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?

Re: Difference between debug and release builds

Jonathan [Darka]12-Sep-07 2:52

Jonathan [Darka]

12-Sep-07 2:52

Read this.

Also, there is an artice on the CodeProject I think but I can't remember its name.

Jonathan Wilkes
Darka[Xanya.net]

Re: Difference between debug and release builds

C^hris L^osinger12-Sep-07 7:10

C^hris L^osinger

12-Sep-07 7:10

it's called Surviving The Release Version.

image processing toolkits | batch image processing

Re: Difference between debug and release builds

carrivick12-Sep-07 5:36

carrivick

12-Sep-07 5:36

Speed is the main difference a debug build will by default have no optimisation, this makes it easier to debug. But you can debug a release build it is just a little harder.

Re: Difference between debug and release builds

Hamid_RT12-Sep-07 6:59

Hamid_RT

12-Sep-07 6:59

See Debugging Release Mode Problems[^].

Error when dumping PE file

sawerr12-Sep-07 2:06

sawerr

12-Sep-07 2:06

Hi In my program i want to use

<br />
BOOL MapAndLoad(<br />
  PSTR ImageName,<br />
  PSTR DllPath,<br />
  PLOADED_IMAGE LoadedImage,<br />
  BOOL DotDll,<br />
  BOOL ReadOnly<br />
);<br />

function in Imagehlp.h .

<br />
CPE::CPE(CString fileName, CString filePath):fileName(fileName),filePath(filePath)<br />
{       LOADED_IMAGE loi;<br />
	::MapAndLoad((LPSTR)(LPCTSTR)fileName, (LPSTR)(LPCTSTR)filePath, &loi,FALSE, TRUE);<br />
	int i = loi.NumberOfSections;<br />
        char q[50];<br />
	sprintf(q,"%d",i);<br />
	MessageBox(NULL, q,NULL,0);<br />
}<br />

When i compiled and execute it. It gives error Messagebox with value -858993460 . I changed my projects setting use multibyte character set. wchar_t to char.

But can not find solution. What is wrong with this code?
How can i fix it?

Thanks.

Re: Error when dumping PE file

David Crow12-Sep-07 2:56

David Crow

12-Sep-07 2:56

sawerr wrote:
What is wrong with this code?

You did not check the return value from MapAndLoad(), nor did you call GetLastError().

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: Error when dumping PE file

sawerr12-Sep-07 3:47

sawerr

12-Sep-07 3:47

I checked the return value, it is not TRUE
MapAndLoad() is not working.
I changed code because of pstr parameters.

CPE::CPE(CString fileName, CString filePath):fileName(fileName),filePath(filePath)<br />
{  <br />
	char *ch1 = strdup(fileName);<br />
	char *ch2 = strdup(filePath);<br />
	MessageBox(NULL, ch1, ch2, 0);<br />
	<br />
	PLOADED_IMAGE loi = ::ImageLoad((PSTR)ch1, (PSTR)ch2);<br />
<br />
	<br />
<br />
	BOOL b = ::MapAndLoad(ch1, ch2, loi,TRUE, TRUE);<br />
	if(b == TRUE)<br />
	{<br />
		MessageBox(NULL, "DONE", NULL, 0);<br />
	}<br />
	<br />
     ULONG i = loi->NumberOfSections;<br />
	    char q[50];<br />
	sprintf(q,"%d",i);<br />
	MessageBox(NULL, q,NULL,0);<br />
   }

fileName and filePath parameters correct (they are coming from CFileDialog) but it gives run-time error in line ULONG i = loi->NumberOfSections;
Unhandled exception at 0x76c977f2 in PEInside.exe: 0xC0000005: Access violation writing location 0x00000004.

Do you have any suggestions?

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