Function mpi::ffi::PMPI_Dist_graph_neighbors

pub unsafe extern fn PMPI_Dist_graph_neighbors(comm: MPI_Comm,
                                               maxindegree: c_int,
                                               sources: *mut c_int,
                                               sourceweights: *mut c_int,
                                               maxoutdegree: c_int,
                                               destinations: *mut c_int,
                                               destweights: *mut c_int)
                                               -> c_int