DAD(const int _rank, const Group& _group, Map* _maps)The normal constructor. Initializes all fields of the DAD object, simply copying the values passed as arguments. The constructor does not allocate any new vector internally. The _maps pointer is simply copied. It is the caller's responsibility to ensure that associated vector persists as long as the constructed DAD record.
DAD(const int _rank, const Group& _group)Simplified constructor. The maps field is left undefined. Since it is publically accessibly, it can be initialized later.
DAD()Default constructor. All fields are left undefined.