title: qt "wildcard" in connect signals
body: <p>In Qt, one can connect a signal to a slot using:</p>
  
  <pre><code>connect(x, SIGNAL(S()), y, SLOT(func()));
  </code></pre>
  
  <p>Where x and y are pointers to instances of a class that inherits from QObject.</p>
  
  <p>I am looking for something like:</p>
  
  <pre><code>connect(*, SIGNAL(S()), y, SLOT(func()));
  </code></pre>
  
  <p>Which would connect anyone sending the signal S to slot func() of y.
  Or:</p>
  
  <pre><code>connect(C, SIGNAL(S()), y, SLOT(func()));
  </code></pre>
  
  <p>where C would design a class (not only an instance), so that all signals S emitted by any instance of C would get connected.</p>
  
  <p>I assume it should be possible to use these "wildcards" instead of 'y' as well:</p>
  
  <pre><code>connect (x, SIGNAL(S()), C, SLOT(func()));
  </code></pre>
  
  <p>would connect signal S of instance x to any instance of class C</p>
  
  <p>How does one do that in Qt?</p>