Function mpi::ffi::MPI_Allgatherv

pub unsafe extern fn MPI_Allgatherv(sendbuf: *const c_void,
                                    sendcount: c_int,
                                    sendtype: MPI_Datatype,
                                    recvbuf: *mut c_void,
                                    recvcounts: *const c_int,
                                    displs: *const c_int,
                                    recvtype: MPI_Datatype,
                                    comm: MPI_Comm)
                                    -> c_int