code snippets

template <typename T>
void List<T>::clear() {
    while (!empty()) {
        pop_front();
    }
}

template <typename T>
List<T>::~List<T>() {
    clear();
    delete head;
    delete tail;
}

template <typename T>
T& List<T>::front() {
    return *begin();
}

template <typename T>
typename List<T>::iterator List<T>::begin() {
    return this->head->next;
}

template <typename T>
void List<T>::push_front(const T & val) {
    insert(begin(), val);
}