[MPI3 Fortran] MPI Data types

[Jeff Squyres]

On May 7, 2009, at 9:29 AM, Bill Long wrote:

> So, inside a wrapper C wrapper routine,  could the information  
> available
> in our Cdesc structure be used create the corresponding MPI datatype,
> and then use that in the internal MPI Call?   This avoids the need  
> for a
> copy at all, does not require any modifications to the Request data
> structure, and also relieves the Fortran user from creating his own  
> MPI
> datatype.  This sounds like the best solution yet.  (Or , maybe that's
> been the plan all along, and I've just figured it out :) ).
>


That would be suitable for a Fortran value-add/add-on library.  It is  
not suitable for the Fortran MPI bindings, unfortunately -- we need to  
preserve pretty much a 1:1 mapping of Fortran functions to C functions  
for the official bindings.

Craig has talked about making a value-add Fortran library that would  
do stuff like this (similar to how the Boost.MPI library did this for C 
++).

-- 
Jeff Squyres
Cisco Systems