> If MPI_Type_struct cannot be used to create a filetype in
> heterogeneous env., how does one specify holes in the file with lb and
> ub? One may be able to specify lb with MPI_Type_resize (even that's
> not clear), but what about ub?
I think MPI_Type_resize will do both. You set the lower bound
explicitly, and the upper bound is implicitly defined by the
extent you ask for. The rule I suggested says that these
bounds have to be set on base-type increments. Am I missing
your point?
> Secondly, if my data structure in memory is an array of structures (in
> C), how do I write it to the file?
Beats me. Maybe we need to resurrect one of the struct constructors
that got moved to the JOD?
John