You'll need to be a bit more specific.  What describe should work fine.

foo.h:
extern MPI_Datatype mydtype;

foo.cc:
#inlclude "foo.h"
MPI_Datatype mydtype;

bar.cc:
#include "foo.h"
void bogus(void) {
  MPI_Datatype foo = mydtype;
}

On Oct 9, 2011, at 4:10 PM, Jack Bryan wrote:

> Hi,
> 
> I need to define a (Open MPI) MPI_Datatype in a header file so that all other 
> files that include it can find it. 
> 
> I also try to use extern to do decleration in .h file and then define them in 
> .cpp file. 
> 
> But, I always get error: 
> 
> undefined reference 
> 
> It is not allowed in Open MPI ? 
> 
> Why ? 
> 
> Any help is really appreciated. 
> 
> Thanks
> _______________________________________________
> users mailing list
> us...@open-mpi.org
> http://www.open-mpi.org/mailman/listinfo.cgi/users


-- 
Jeff Squyres
jsquy...@cisco.com
For corporate legal information go to:
http://www.cisco.com/web/about/doing_business/legal/cri/


Reply via email to