[Qt-interest] Error in defining a static data member to a class

[Jason H]

Static member variables have to be allocated in a cpp, so that there is only one copy. The class ceclaration is availible to all files, the definition is only avavilible to one file. This same file should also declare the allocation for static member variables.  

This is true on your platform as it is on mine (MSVC)





________________________________
From: Akshey Jawa <aksheyjawa at gmail.com>
To: Constantin Makshin <dinosaur-rus at users.sourceforge.net>
Cc: Qt Interest <qt-interest at trolltech.com>
Sent: Thu, October 29, 2009 12:36:10 PM
Subject: Re: [Qt-interest] Error in defining a static data member to a class

Thanks a lot. The in-class definition gave a compilation error. But the defining in .cpp file worked! 
Is it some problem with Qt or the same applies to other compilers too ? I am not an experienced programmer.

Thanks,
Akshey


On Thu, Oct 29, 2009 at 1:36 AM, Constantin Makshin <dinosaur-rus at users.sourceforge.net> wrote:

Either define it in the class declaraion
>
>>class ClassName
>>{
>>     static int temp = 0;
>>};
>
>>or in one of your .cpp files
>
>>// someclass.h
>>class ClassName
>>{
>>     static int temp;
>>};
>
>>// someclass.cpp
>>#include "someclass.h"
>>int ClassName::temp = 0;
>
>>On Wed, 28 Oct 2009 14:21:46 +0300, Akshey Jawa <aksheyjawa at gmail.com>
>>wrote:
>
>> Hi,
>>>
>>> I am getting an error in defining a static data member to a class. The
>>> declaration of the static member does not give any error but when I
>>> define the variable then I get an the error. Example--
>>>
>>> I got error for this statement-
>>> *int ClassName::temp=0;*
>>>
>>> *Error:*  multiple definition of `ClassName::temp'.
>>> first defined here:
>>> main.o:/usr/include/c++/4.2/bits/locale_facets.tcc:2560
>>>
>>> I have tried changing the names of the identifiers and also tried
>>> introducing static data members in some other working code, but I get
>>> similar errors. I am using Qt Creator but I get same error on command
>>> line also.
>>>
>>> Please help
>>>
>>> Regards,
>>> Akshey
>
>--
>>Constantin Makshin
>>_______________________________________________
>>Qt-interest mailing list
>Qt-interest at trolltech.com
>http://lists.trolltech.com/mailman/listinfo/qt-interest
>



      
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