[Qt-interest] 64-bit conditional compile

[Andre Somers]

On 12-5-2010 4:07, Berry Octave wrote:
> Le mardi 11 mai 2010, vous avez écrit
>    
>> What is the Qt way to conditionally compile for 64-bit or 32-bit
>> architectures?
>>
>> qglobal.h has definitions for Q_WS_MAC64 and Q_OS_WIN64, but I don't
>> see anything for generic 64-bit compile.
>>
>> Thanks!
>>
>> John Weeks
>>
>> WaveMetrics, Inc.
>> Phone (503) 620-3001
>> Fax   (503) 620-6754
>> email   support at WaveMetrics.com
>>      
> A trick would be to use the pointer size.
>
> if (sizeof(void *) == 4)
> 	// Do 32bits stuff
>
> if (sizeof(void *) == 8)
> 	// Do 64 bits stuff.
>
> Regards
> Berry Octave
>    
That is not really a conditional compile, I'd say. That is a runtime 
evaluation, which can be expensive if you do it often.
What I currently do is just define a variable in my project by adding it 
to the qmake command (very originally called ARCH), and use that in my 
.pro file to do conditional compilation and set defines to use in the code.

André