title: What are the details of "Objective-C Literals" mentioned in the Xcode 4.4 release notes?
body: <p>I was going through the release notes for Xcode 4.4 and noticed this:</p>
  
  <blockquote>
    <p>LLVM 4.0 Compiler</p>
    
    <p>Xcode now includes the Apple LLVM Compiler version 4.0, including the following newObjective-C language features:
    [...]<br>
    - Objective-C literals: create literals for NSArray, NSDictionary, and NSNumber, just the same as the literals for NSString</p>
  </blockquote>
  
  <p>I'm intrigued about this feature. It's not entirely clear to me just how literals for <code>NSString</code> work and how one could use them on <code>NSArray</code>, <code>NSDictionary</code>, and <code>NSNumber</code>.</p>
  
  <p>What are the details?</p>