group_out = group_root; /* exit with root's group */
} else {
if(color != MPI_UNDEFINED) {
Request::recv(&group_out, 1, MPI_PTR, 0, system_tag, this, MPI_STATUS_IGNORE);
} /* otherwise, exit with group_out == nullptr */
}
group_out = group_root; /* exit with root's group */
} else {
if(color != MPI_UNDEFINED) {
Request::recv(&group_out, 1, MPI_PTR, 0, system_tag, this, MPI_STATUS_IGNORE);
} /* otherwise, exit with group_out == nullptr */
}