title: Swift 3: atomic_compare_exchange_strong
body: <p>Getting following warning in Xcode 8 / Swift 3:</p>
  
  <pre><code>warning: 'OSAtomicCompareAndSwap32Barrier' was deprecated in OS X 10.12:
           Use atomic_compare_exchange_strong() from &lt;stdatomic.h&gt; instead
  </code></pre>
  
  <p>Attempt to use function <code>atomic_compare_exchange_strong</code> in Swift code leads compiler error:</p>
  
  <pre><code>error: use of unresolved identifier 'atomic_compare_exchange_strong'
  </code></pre>
  
  <p>Importing <code>Darwin</code> or <code>CoreFoundation</code> modules does not solve problem.</p>
  
  <p>What module should I import in order to get symbol for <code>atomic_compare_exchange_strong</code>?</p>
  
  <p>Thank you!</p>