Its quite common to see code that isn't even valid for MPI, such as a switch statement using predefined datatypes. As there isn't any want to check handle similarity for datatypes, we really need to require equality. As you note, this doesn't affect any implementations. Bill On Jul 18, 2008, at 3:16 PM, Jeff Squyres wrote:

On Jul 18, 2008, at 3:08 PM, William Gropp wrote:

...

Any behavior other than branch A violates the principle of least surprise.

I assume that most MPI implementations will have the values be equal just by how their f2c/c2f engines work (OMPI will). I was just wondering if it's necessary to *mandate* that behavior.

Do apps really check handle equality? If so, I agree that anything other than path A violates the law of least astonishment. I assumed that not many apps do this, but I probably don't have a good basis for reference.

-- Jeff Squyres Cisco Systems

_______________________________________________ mpi-22 mailing list mpi-22_at_[hidden] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-22

William Gropp Paul and Cynthia Saylor Professor of Computer Science University of Illinois Urbana-Champaign *