Deprecated methods

With time, there are more and more deprecated methods used:

• bool QVariant::operator<=(const QVariant&) const

-void KWindowEffects::slideWindow(WId, KWindowEffects::SlideFromLocation, int)

-quint32 KWayland::Client::PlasmaWindow::internalId() const

-int qrand()

and many many others.

What do you think of updating them?