Thanks bringing up this important point. It can be viewed as another
reason for MPI implementations to publish or otherwise make available the
description of an MPI derived DataType. For example, it would permit
"foreign" processes to dynamically construct their own instantiation of
the type and "foreign process" data transfer operations; i.e., a schedule
for mapping incoming data to memory.
On Mon, 6 Nov 1995, Robert George wrote:
> Steve, Richard,
> Raw C structures are not portable even if you have a homogeneous architecture.
> Many C compilers play games with the ordering of data elements within a
> structure as a means of packing data (such as grouping all the char`s together
> at the end of the structure). The ANSI C specification specifically says that
> they make no assumptions about how the compiler implements a C structure,
> except that it must not start or end with a "hole."
> The specification later says that if you don't like this, then use XDR, or the
> ISO data format standard.