char *recv_ptr = (char *) recv_buff;
// get size of the communicator, followed by rank
char *recv_ptr = (char *) recv_buff;
// get size of the communicator, followed by rank
// get size of single element's type for recv buffer
recv_extent = smpi_datatype_get_extent(recv_type);
// get size of single element's type for recv buffer
recv_extent = smpi_datatype_get_extent(recv_type);