#ifndef CLASS_H
#define CLASS_H
#include <QObject>

namespace enums
{
    enum class Cards
    {
        Clubs,
        Diamonds,
        Hearts,
        Spades
    };
}

class Class : public QObject
{
    Q_OBJECT

public:
    Class() {}

signals:
    void cardPicked(enums::Cards card);

public slots:
    void setCard(enums::Cards card) {}
};

#endif // CLASS_H

#include <QCoreApplication>
#include "Class.h"

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

    QObject::connect(&c, &Class::cardPicked, &c, &Class::setCard);

    return a.exec();
}