/*D
   MPI_Exscan - Computes the exclusive scan (partial reductions) of data on a collection of processes

Synopsis:
.vb
int MPI_Exscan(const void *sendbuf, void *recvbuf, int count,
               MPI_Datatype datatype, MPI_Op op, MPI_Comm comm)
.ve
.vb
int MPI_Exscan_c(const void *sendbuf, void *recvbuf, MPI_Count count,
                 MPI_Datatype datatype, MPI_Op op, MPI_Comm comm)
.ve

Input Parameters:
+ sendbuf - starting address of send buffer (choice)
. count - number of elements in input buffer (non-negative integer)
. datatype - data type of elements of input buffer (handle)
. op - operation (handle)
- comm - intra-communicator (handle)

Output Parameters:
. recvbuf - starting address of receive buffer (choice)

Notes:
  'MPI_Exscan' is like 'MPI_Scan', except that the contribution from the
   calling process is not included in the result at the calling process
   (it is contributed to the subsequent processes, of course).

.N collops

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_BUFFER
.N MPI_ERR_COMM
.N MPI_ERR_COUNT
.N MPI_ERR_OP
.N MPI_ERR_TYPE
.N MPI_ERR_OTHER

D*/

