[Mpi3-bwcompat] MPI_Count mixing with int...

[Fab Tillier]

Rajeev Thakur wrote on Thu, 8 Jul 2010 at 12:52:58

>> As an aside, can count ever be larger than size_t?
> 
> Probably not in the communication or I/O functions since count refers to
> the number of items in the memory buffer, but it could be for the
> datatype constructor functions since datatypes can represent file layout.

How would you use a datatype that is larger than your address space?  You can't read or write it, you can't send or receive it, you can't pack/unpack it...

Am I missing something and a datatype like this would be useful?

-Fab