title: Why is a QList not derived from a QObject?
body: <p>I wanted to create a <code>QObservableCollection</code> wrapper around a <code>QList</code>(using an internal <code>QList</code> for implementation and forwarding all calls while emiting some sort of CollectionsChanged signal for functions that change the collection), but I see that <code>QList</code> does not inherit from <code>QObject</code>.</p>
  
  <p>I believe you need to inherit from <code>QObject</code> to emit Qt Signals. So I'd need to inherit from <code>QObject</code> for my QObeservableCollection.</p>
  
  <p>But <code>QList</code> and <code>QVector</code> and the other Qt collections doen't inherit from <code>QObject</code>, so I imagine their must be some sort of downside or problem making a collection.</p>
  
  <p>I see that QSignalSpy  inherits from both  <code>QObject</code> and <code>QList&lt;QList&lt;QVariant&gt;&gt;</code> so maybe they just didn't see a reason to inherit from QObject?</p>