title: How do initializations of C structs work in iOS's Objective-C?
body: <p>From <a href="https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CGGeometry/Reference/reference.html#//apple_ref/doc/c_ref/CGSize" rel="nofollow">https://developer.apple.com/library/ios/documentation/GraphicsImaging/Reference/CGGeometry/Reference/reference.html#//apple_ref/doc/c_ref/CGSize</a> :</p>
  
  <pre><code>struct CGSize {
     CGFloat width;
     CGFloat height;
  };
  typedef struct CGSize CGSize;
  </code></pre>
  
  <p>CGSize is an unadorned C struct and doesn't accept messages.</p>
  
  <p>What are appropriate ways to (in my case) create a CGsize with its dimensions to be 0?</p>
  
  <p>If I were working straight C, it would be a use case for calloc() or whatnot. What is the Objective-C idiom for this use case?</p>