QJSEngine and QStringList properties handling, a potential performance issue

main.cpp

#include <QCoreApplication>
#include <QDebug>
#include <QQmlApplicationEngine>

class Object : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QStringList strings READ strings CONSTANT)

public:
    QStringList strings() const
    {
        static unsigned callCounter = 0;
        qDebug() << Q_FUNC_INFO << "called" << ++callCounter << "times";

        QStringList ret;
        for (int i = 0; i < 10; ++i)
            ret.append(QString::number(i));

        return ret;
    }
};

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

    QJSEngine engine;
    engine.installExtensions(QJSEngine::ConsoleExtension);

    qmlRegisterUncreatableType<Object>("App", 1, 0, "Object", QStringLiteral("Use 'object'"));

    engine.globalObject().setProperty(QStringLiteral("object"), engine.newQObject(new Object));

    // Note how the following snippet causes Object::strings to be called
    // 2 times + as many times as there are items in the list.
    engine.evaluate(QStringLiteral("console.log(object.strings)"));
}

#include "main.moc"

output.txt

QStringList Object::strings() const called 1 times
QStringList Object::strings() const called 2 times
QStringList Object::strings() const called 3 times
QStringList Object::strings() const called 4 times
QStringList Object::strings() const called 5 times
QStringList Object::strings() const called 6 times
QStringList Object::strings() const called 7 times
QStringList Object::strings() const called 8 times
QStringList Object::strings() const called 9 times
QStringList Object::strings() const called 10 times
QStringList Object::strings() const called 11 times
QStringList Object::strings() const called 12 times
js: [0,1,2,3,4,5,6,7,8,9]