title: Extension of String - Error received 'No Member'
body: <p>I have created an extension of String:</p>
  
  <pre><code>extension String {
      var cSym:String? {
          return CurrencyConversion.getCurrencySymbolWithCode(self)
      }
  }
  </code></pre>
  
  <p>When I go to use the extension I can see it and Xcode points to the extension fine, but then when I go to run I get and error stating:</p>
  
  <blockquote>
    <p>Value of 'String' has no member 'cSym'</p>
  </blockquote>
  
  <pre><code>class func getCurrency(code : String) -&gt; String {
      return code.cSym ?? "$"
  }
  </code></pre>
  
  <p>I have been looking at the Apple documentation <a href="https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Extensions.html" rel="nofollow">https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Extensions.html</a> and I can't see what the problem is. I have copied and pasted the code snippet from the documentation as well and I get the exact same error for the Double.</p>
  
  <p>Maybe it's a Swift2.1 issue?</p>