title: Ambiguous reference to member when using ceil or round
body: <p>I am just trying to use the <code>ceil</code> or <code>round</code> functions in Swift but am getting a compile time error:</p>
  
  <blockquote>
    <p>Ambiguous reference to member 'ceil'.</p>
  </blockquote>
  
  <p>I have already imported the <code>Foundation</code> and <code>UIKit</code> modules. I have tried to compile it with and without the <code>import</code> statements but no luck. Does anyone one have any idea what I am doing wrong?
  my code is as follow;</p>
  
  <pre><code>import UIKit
  
  @IBDesignable class LineGraphView: GraphView {
  override func setMaxYAxis() {
              self.maxYAxis = ceil(yAxisValue.maxElement())
  
      }
     }
  </code></pre>