struct foo
{
    Data  data;
    foo*  next;
    foo** prevNext;
};

HashTable<foo> hash;

template <class T>
void HashTable<T>::insert(T* x)
{
    int bucket  = hashFunc(x->data);
    T** xPtr    = &elements_[bucket];
    x->next     = *xPtr;
    x->prevNext = xPtr;

    if (x->next)
        x->next->prevNext = &x->next;

    *xPtr = x;
}

template<class T>
void HashTable<T>::remove(T* x)
{
    if (x->next)
        x->next->prevNext = x->prevNext;

    *x->prevNext = x->next;
}

template<class T>
T* HashTable<T>::find(Data& data)
{
    int bucket = hashFunc(data);

    T* ptr = elements_[bucket];
    while (ptr != 0)
    {
        if(ptr->data == data)
            return ptr;
        ptr = ptr->next;
    }
    return 0;
}