MPI_File_iwrite_at_c - Nonblocking write using explicit offset

fh     - file handle (handle)
       offset - file offset (nonnegative integer)
       buf    - initial address of buffer (choice)
       count  - number of elements in buffer (nonnegative integer)
       datatype
              - datatype of each buffer element (handle)

       MPI_File_iwrite_at_c -  Nonblocking write using explicit offset

       All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have an additional argument ierr at the
       end of the argument list.  ierr is an integer and has the same meaning as the return value of the routine
       in C.  In Fortran, MPI routines are subroutines, and are invoked with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

                                                    1/21/2022                            MPI_File_iwrite_at_c(3)

request
              - request object (handle)

       #ifdef HAVE_MPI_GREQUEST
       #include "mpiu_greq.h"
       #endif
       int MPI_File_iwrite_at_c(MPI_File fh, MPI_Offset offset, ROMIO_CONST void *buf,
       MPI_Count count, MPI_Datatype datatype, MPIO_Request * request)