title: Stray @ in program with NSDictionary definition
body: <p>In the course of following a howto online, I came across the following code:</p>
  
  <pre><code>NSDictionary *address = @{
    (NSString *)kABPersonAddressStreetKey: _address.text,
    (NSString *)kABPersonAddressCityKey: _city.text,
    (NSString *)kABPersonAddressStateKey: _state.text,
    (NSString *)kABPersonAddressZIPKey: _zip.text
  };
  </code></pre>
  
  <p>Which will not compile in XCode 4.5.1. I get two errors:</p>
  
  <ol>
  <li>Stray '@' in program</li>
  <li>Expected '}' before ':' token</li>
  </ol>
  
  <p>What am I missing here? Also, where do I find documentation on this shortcut declaration of an NSDictionary object? It's awfully hard to Google syntax like this.</p>