I would like to be able to add two QList objects. For example:

QList<int> b;
b.append(10);
b.append(20);
b.append(30);

QList<int> c;
c.append(1);
c.append(2);
c.append(3);

QList<int> d;
d = b + c;

For this reason, I decided to subclass the QList and to overload the operator+.

Here is my code:

class List : public QList<int>
{
public:
    List() : QList<int>() {}

    // Add QList + QList
    friend List operator+(const List& a1, const List& a2);
};

List operator+(const List& a1, const List& a2)
{
    List myList;

    myList.append(a1[0] + a2[0]);
    myList.append(a1[1] + a2[1]);
    myList.append(a1[2] + a2[2]);

    return myList;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    List b;
    b.append(10);
    b.append(20);
    b.append(30);

    List c;
    c.append(1);
    c.append(2);
    c.append(3);

    List d;
    d = b + c;

    List::iterator i;
    for(i = d.begin(); i != d.end(); ++i)
        qDebug() << *i;

    return a.exec();
}

, the result is correct but I am not sure whether this is a good approach. I would like to ask whether there is better solution?