Careful, here! The MPI Forum has been exceedingly fickle on this point. Most
recently, for example, we did decide that the MPI-IO datatypes should be full
citizens i.e. *not* layered. So my guess is that in the true spirit of
compromise, we'll probably end up with the worst of both worlds; the coupling
will be just enough to prevent layerable implementations but not strong enough
to be really useful.
-- Eric Salo Silicon Graphics salo@sgi.com