#include <QApplication>
#include <QDebug>

enum class color {   red,  green, blue };

Q_DECLARE_METATYPE(color)

int main(int argc, char** argv)
{
    QApplication app(argc, argv);

    QVariant v1 = QVariant::fromValue(color::green);
    QVariant v2 = 1;
    qDebug() << (v1 == v2);
    qDebug() << (v2 == v1);

    return app.exec();
}