title: CTLine or NSAttributedString -- get image bounds without a graphics context?
body: <p>Is this possible?  Basically, I have a bunch of NSAttributedString objects and corresponding CTLine objects.  I want to get the image bounds before the drawRect stage.  So at this point, there is nothing to draw into.  I will then use these image bounds to decide exactly what I need to create for drawing.</p>
  
  <p>EDIT:  Another measurement of the size would probably work just fine.  But calling the deceptively named CTLineGetTypographicBounds function only returns the width.  If I pass in addresses of ascent and descent floats, they come back as zero.</p>
  
  <p>EDIT:  The given answer works great in MacOS.  Can anyone do it in iOS?</p>