title: extern NSString not accessible since Swift 2.2
body: <p>Since the update to Xcode 7.3 with Swift 2.2 I am not able to access variables from an external Objective-C Library.</p>
  
  <p>Since today I was able to access this variables:</p>
  
  <pre><code>extern NSString* const DEFAULT_URL;  
  </code></pre>
  
  <p>This is defined in an Objective-C Header file from a precompiled .a framework.</p>
  
  <p>In my swift code I only had to call <code>DEFAULT_URL</code>.</p>
  
  <p>Since Swift 2.2 I get the following errror:</p>
  
  <pre><code>Use of unresolved identifier 'DEFAULT_URL'  
  </code></pre>
  
  <p>I am able to access the classes and methods of this framework, but I can't access <code>extern NSStrings</code>.</p>
  
  <p>Any ideas how to fix this?</p>