template<class K, class T, class HashFnK = StdHash<K>, class HashFnT = StdHash<T>>
class VectorBiMap
	: public Index<K, HashFnK>
	, public Index<T, HashFnT>
{

	//following the api
//find T with K hash
//find K with T hash
};

template<class K, class T, class HashFnK = StdHash<K>, class HashFnT = StdHash<T>>
class VectorBiMap2
	: public MoveableAndDeepCopyOption<VectorBiMap2<K, T, HashFnK, HashFnT> >
	, public AMap< K, T, Vector<T>, HashFnK > 
{
	typedef AMap< K, T, Vector<T>, HashFnK > B;
	HashBase hash2;
	HashFnT hashfn2;
	
	//following the api
//find T with K hash
//find K with T hash
};