title: How to implement collision effects in a game?
body: <p>I building a game with QT. Every objects on my GraphicsScene inherits from GraphicsPixmapItem (Player, Obstacles, bombs...). I would like to implment collision effects. For example when the player gets hover a bonus he can pick it. 
  With the QT framework I can get the collidings items but I don't know which type they are as there isn't instanceof function. Any tips ?</p>
  
  <p>edit: I get the collision "event" the thing I want to do is handle the different collisions. I made another <a href="https://stackoverflow.com/questions/1876179/how-to-handle-multiple-collision-type-in-c">question</a> with better wording.</p>