title: Swift conversion: ERROR - UnsafeMutablePointer
body: <p>I am attempting to convert my Swift 2 code into the latest syntax(Swift 3). I am receiving the following error:</p>
  
  <blockquote>
    <p>Cannot invoke initializer for type 'UnsafeMutablePointer&lt;CUnsignedChar>' with an argument list of type '(UnsafeMutableRawPointer!)</p>
  </blockquote>
  
  <p>Swift 2 Code:</p>
  
  <pre><code>let rawData = UnsafeMutablePointer&lt;CUnsignedChar&gt;(calloc(height * width * 4, Int(sizeof(CUnsignedChar))))
  </code></pre>
  
  <p>Can someone please help me resolve this conversion syntax issue?</p>