#include <QCoreApplication>
#include <QObject>
#include <QDebug>
#include <QSettings>
#include <QSharedPointer>
#include <QTimer>

class Logger: public QObject
{
public:
  void onAboutToQuit()
  {
    QSettings s;
    qDebug() << "filename" << s.fileName();
    QVariant variant = s.value("mySetting", QVariant(true));
    qDebug() << "valid?" << variant.isValid();
    qDebug() << "variant" << variant;
    bool value = variant.value<bool>();
    qDebug() << "value" << value;
    s.setValue("mySetting", value);
    value = s.value("mySetting").value<bool>();
    s.sync();
    qDebug() << "value" << value;
    qDebug() << "status" << s.status();
  }
};

int main(int argc, char *argv[])
{
  QCoreApplication a(argc, argv);
  a.setOrganizationName("QtCompany");
  a.setOrganizationDomain("www.qt-project.org");
  a.setApplicationName("TestSettings");
  a.setApplicationVersion("0.0.1");
  QSharedPointer<Logger> l(new Logger);
  QObject::connect(&a, &QCoreApplication::aboutToQuit,
    l.data(), &Logger::onAboutToQuit);
  QSharedPointer<QTimer> t(new QTimer);
  QObject::connect(t.data(), &QTimer::timeout, &a, &QCoreApplication::quit);
  t->setInterval(0);
  t->start();
  return a.exec();
}