On Jun 30, 2011, at 2:48 PM, Rolf Rabenseifner wrote:

Main decision that we must do:
- How must we define
  -- MPI_Op_create (with a callback with choice buffer), and
  -- MPI_Errhandler_create (without such a choice buffer callback)?

- Main question for this:
  Which rules do we have for callbacks and BIND(C)?
  (a full list of all callbacks are in MPI-2.2, page 617)