title: Make Doxygen document a struct/class defined inside a macro call
body: <p>I have this <a href="https://github.com/marciof/Eon/blob/master/library/util.h#L207" rel="nofollow"><code>PACKED</code> macro</a>, that receives a <a href="https://github.com/marciof/Eon/blob/master/core/architecture/x86/multiboot/Boot_Device.h#L21" rel="nofollow"><code>struct</code> definition</a> and returns it with a compiler annotation to make it packed.</p>
  
  <p>For example:</p>
  
  <pre><code>/**
   * ...
   */
  PACKED(struct A {
      /**
       * ...
       */
      int x;
  });
  </code></pre>
  
  <p>I have tried several Doxygen options to include that documentation, but I've had no success so far. Closest I've come up with is this:</p>
  
  <pre><code>ENABLE_PREPROCESSING = YES
  PREDEFINED = PACKED(type)=type
  MACRO_EXPANSION = YES
  </code></pre>
  
  <p>But that messes up the <code>struct</code> and members' documentation (confirmed via <code>doxygen -d Preprocessor</code>).</p>
  
  <p>Ideas?</p>