Implementing Binary Search

template <typename T, class P>
typename BST<T,P>::Iterator BST<T,P>::Includes (const T& t) const
{
  Node * n = root_;
  while(n != nullptr)
  {
    if (pred_(t,n->value_))         // go left
      n = n->lchild_;
    else if (pred_(n->value_,t))    // go right
      n = n->rchild_;
    else                            // found
      return (Iterator)n;           // convert to iterator and return
  }
  return End();
}

• Problem: what is an Iterator?
• Several answers to this question in later chapter that make the code above work.
• What other safe thing can we return and still be useful?