[mpi-21] Proposal: MPI_OFFSET built-in type

Robert Latham robl at [hidden]
Thu Jan 24 10:41:52 CST 2008

I hope this is less contentious than adding 'const' keywords...

I would like to propose a new built-in type MPI_OFFSET, defined to be
a type corresponding to INTEGER(KIND=MPI_OFFSET_KIND) or MPI_Offset

This is a minor addition to the standard, which would have no impact
on existing code while serving to simplify code which exchanges file
offsets among processes.

There is a workaround in the standard: a user can define a type from

 MPI_Type_contiguous(sizeof(MPI_Offset), MPI_BYTE, &offtype);

However, it would clearly be more convienient to operate on built-in

Corresponding C type: long long int
Corresponding Fortran type: INTEGER(KIND=MPI_OFFSET_KIND)


Rob Latham
Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
Argonne National Lab, IL USA                 B29D F333 664A 4280 315B

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