void MyApp::load(QQmlApplicationEngine &engine)
{
    const QUrl url(QStringLiteral("qrc:/qml/myapp.qml"));
    connect(&engine, &QQmlApplicationEngine::objectCreated, this, [url](QObject *obj, const QUrl &objUrl)
    {
        if (!obj && url == objUrl)
            QCoreApplication::exit(-1);
    }, Qt::QueuedConnection);

    engine.load(url);
}