Re: new filter proposal
Rajeev Thakur (thakur@mcs.anl.gov)
Wed, 16 Apr 1997 12:24:45 -0500
> Date: Wed, 16 Apr 1997 09:29:04 -0700
> From: johnmay@llnl.gov (John May)
>
> What I intended here was to permit an implementation to send a
> datatype that was constructed out of a type that the user passed
> to a read or write. For example, an implementation might build
> a contiguous type using the datatype and the count, rather
> than compute the tiling itself. I didn't mean that the
> implementation might cut a datatype into pieces and pass in
> pieces, although I guess that could be permitted too. So
> according to my understanding of how MPI uses "derived," I
> think I said what I meant. Whether what I meant is right is
> another question...
>
> John
To do what you want with the "position" argument, you would need to
allow the datatype to be cut up, because
MPI_Read(buf, count=1, large_datatype, ...)
is possible.
Rajeev