QMetaObject::constructorCount returns 0

class MyItem : public QObject {
  Q_OBJECT
  Q_PROPERTY(QString strfield READ strfield)
  Q_CLASSINFO("foo", "bar")
  QString m_strfield;
public:
  explicit MyItem(QObject *parent = nullptr);
  MyItem(int, int, char *, QString);
  QString strfield() const \{ return m_strfield; }
};

for (int typeId = QMetaType::User;; typeId++) {
  if (!QMetaType::isRegistered(typeId)) break;
  qDebug() << "found metatype" << QMetaType::typeName(typeId);
  const QMetaObject* mo = QMetaType::metaObjectForType(typeId);
  qDebug() << "class info";
  for (int i = 0; i < mo->classInfoCount(); i++) {
    qDebug() << "classInfo" << mo->classInfo(i).name() << mo->classInfo(i).value();
  }
  qDebug() << "Constructors" << mo->constructorCount();
  for (int ctorIndex = 0; ctorIndex < mo->constructorCount(); ctorIndex++) {
    QMetaMethod ctor = mo->constructor(ctorIndex);
    qDebug() << "constructor" << ctor.name() << "signature" << ctor.methodSignature();
  }
  qDebug() << "Methods";
  for (int methodIndex = 0; methodIndex < mo->methodCount(); methodIndex++) {
    QMetaMethod method = mo->method(methodIndex);
    qDebug() << "method" << method.name() << "signature" << method.methodSignature(); 
  }
}