how to detect OS architecture?

[Gary Willoughby]

On Monday, 16 December 2013 at 10:54:15 UTC, Hugo Florentino 
wrote:
> Hi,
>
> I am writing a launcher to make a Windows application portable, 
> but since this application supports both x86 and x86_64, I 
> would like to detect the architecture of the OS my launcher is 
> being run on, in order to launch the proper executable.
>
> How can I do this?
>
> Regards, Hugo

version (Windows)
{
     version (X86_64)
     {
         // 64bit code.
     }

     version (X86)
     {
         32bit code.
     }
}