title: Can constraintsWithVisualFormat be used with an unknown number of views?
body: <p>Assuming I have an array of UIViews that are created dynamically and I'd add them to the same parent view, can I use constraintsWithVisualFormat to set set constraints so that they are vertically stacked? The ascii art required in constraintsWithVisualFormat doesn't seem to allow that.</p>
  
  <p>If not, what's the best practice to do this?</p>
  
  <p>Thanks!</p>