CS35 List Wrapper for STL List

#pragma once
/* Copyright (c) 2018
   Swarthmore College Computer Science Department, Swarthmore PA
   A. Danner, M. Gagne, J. Brody, Z. Palmer, A. Soni, L. Meeden
   Distributed as course material for Spring 2018
   CPSC 035: Data Structures and Algorithms
 */

#include <iterator>
#include <list>
#include <stdexcept>

#include <cs35/list.h>

using std::list;
using std::runtime_error;

template <typename T>
class STLList : public List<T> {
public:
    int getSize();
    bool isEmpty();
    T peekHead();
    T peekTail();
    T get(int i);
    void insertAtHead(T value);
    void insertAtTail(T value);
    T removeHead();
    T removeTail();
private:
    list<T> actualList;
};

template <typename T>
int STLList<T>::getSize() {
    return actualList.size();
}

template <typename T>
bool STLList<T>::isEmpty() {
    return actualList.empty();
}

template <typename T>
T STLList<T>::peekHead() {
    if (actualList.empty()) {
        throw runtime_error("peekHead: empty list");
    } else {
        return actualList.front();
    }
}

template <typename T>
T STLList<T>::peekTail() {
    if (actualList.empty()) {
        throw runtime_error("peekTail: empty list");
    } else {
        return actualList.back();
    }
}

template <typename T>
T STLList<T>::get(int i) {
    if (i<0 || i>=actualList.size()) {
        throw runtime_error("get: invalid index");
    }
    return *(std::next(actualList.begin(), i));
}

template <typename T>
void STLList<T>::insertAtHead(T value) {
    actualList.push_front(value);
}

template <typename T>
void STLList<T>::insertAtTail(T value) {
    actualList.push_back(value);
}

template <typename T>
T STLList<T>::removeHead() {
    if (actualList.empty()) {
        throw runtime_error("removeHead: empty list");
    } else {
        T value = peekHead();
        actualList.pop_front();
        return value;
    }
}

template <typename T>
T STLList<T>::removeTail() {
    if (actualList.empty()) {
        throw runtime_error("removeTail: empty list");
    } else {
        T value = peekTail();
        actualList.pop_back();
        return value;
    }
}