title: Swift 3 mutating functions missing ('...inPlace' methods)
body: <p>In Swift 2.3, we can write something like this:</p>
  
  <pre><code>var rect = CGRect(...)
  rect.offsetInPlace(dx: 15, dy: 0)
  </code></pre>
  
  <p>to move a rect 15pt to the right.</p>
  
  <p>However in Swift 3, it seems like this function does no longer exist.
  When inspecting the <code>CGRect</code> interface we can only see the non mutating variant <code>offsetBy(dx:, dy:)</code>. This is also true in all the places we've usually used mutating functions (named <code>...inPlace</code>). I have already searched the Swift evolution repo on GitHub, but couldn't find any notes about this.</p>
  
  <p>Have the mutating variants been removed? Is the remaining function automatically mutating depending on whether or not the return value is used? IMHO, it would be a shame, if they have actually been removed, because they used to be very convenient when doing code based layout, etc.</p>