enqueue_two.cc

template<typename T>
inline void Queue<T>::Enqueue(const T &element) {
  if (this->data_->IsEmpty()) {
    this->data_->AddToEnd(element);
  } else {
    Node<T> *node = this->data_->PeekHead();
    if (node->data_ != element) {
      // Issue here when inserting something into the first node.
      while (node->next_ != nullptr) {
        node = node->next_;
        cout << element << " " << node->data_ << endl;
        if (element < node->data_) {
          this->data_->AddBeforeNode(element, node);
          return;
        }
      }
      this->data_->AddToEnd(element);
    } // else, the element already exists in the Queue, DoNothing();
  }
}