title: Swift Error: Cannot convert value of type 'ArraySlice' to expected argument type
body: <p>I'm getting this error and am new to Swift. I want to take the last 5 points of an array >= 5, and pass those 5 points as an array argument to a function. How can I achieve this and get past this error?</p>
  
  <p>Cannot convert value of type 'ArraySlice' to expected argument type '[CGPoint]'</p>
  
  <pre><code>if (self.points?.count &gt;= 5) {
      let lastFivePoints = self.points![(self.points!.count-5)..&lt;self.points!.count]
      let angle = VectorCalculator.angleWithArrayOfPoints(lastFivePoints)
  }
  </code></pre>