title: Usage of withMemoryRebound with Apples Swift 3 beta 6
body: <p>I have the following Problem. I want to convert my old function (worked until Swift 3 beta 5):</p>
  
  <pre><code>func binarytotype &lt;T&gt; (_ value: [UInt8], _: T.Type) -&gt; T
  {
      return value.withUnsafeBufferPointer
      {
          return UnsafePointer&lt;T&gt;($0.baseAddress!).pointee
      }
  }
  </code></pre>
  
  <p>To Swift 3 beta 6 Syntax. This function converts an array of UInt8 to another type, for example:</p>
  
  <pre><code>let b: [UInt8] = [1,2,3,4,5,6,7,8]
  var number: Double = binarytotype(b, Double.self)
  </code></pre>
  
  <p>But for now this does not work any more in beta 6 and I have to use withMemoryRebound but I really do not know, how to make it run. Can anybody help me?</p>
  
  <p>The reverse function of this was:</p>
  
  <pre><code>func typetobinary &lt;T&gt; (_ value: T) -&gt; [UInt8]
  {
      var v: T = value
      return withUnsafePointer(to: &amp;v)
      {
          Array(UnsafeBufferPointer(start: UnsafePointer&lt;UInt8&gt;($0), count: MemoryLayout&lt;T&gt;.size))
      }
  }
  </code></pre>
  
  <p>This does not work any more, too. Same problem. Both are needed for some of my projects. This reverse function was called as:</p>
  
  <pre><code>var binary: [UInt8] = typetobinary(number)
  </code></pre>