title: Documenting preprocessor defines in Doxygen
body: <p>Is it possible to document preprocessor defines in Doxygen? I expected to be able to do it just like a variable or function, however the Doxygen output appears to have "lost" the documentation for the define, and does not contain the define itself either.</p>
  
  <p>I tried the following</p>
  
  <pre><code>/**My Preprocessor Macro.*/
  #define TEST_DEFINE(x) (x*x)
  </code></pre>
  
  <p>and</p>
  
  <pre><code>/**@def TEST_DEFINE
  
     My Preprocessor Macro.
  */
  #define TEST_DEFINE(x) (x*x)
  </code></pre>
  
  <p>I also tried putting them within a group (tried defgroup, addtogroup and ingroup) rather than just at the "file scope" however that had no effect either (although other items in the group were documented as intended).</p>
  
  <p>I looked through the various Doxygen options, but couldn't see anything that would enable (or prevent) the documentation of defines.</p>