title: When should you use macros instead of inline functions?
body: <p>In a previous <a href="https://stackoverflow.com/questions/1638437/given-an-angle-and-length-how-do-i-calculate-the-coordinates">question</a> what I thought was a good answer was voted down for the suggested use of macros</p>
  
  <pre><code>#define radian2degree(a) (a * 57.295779513082)
  #define degree2radian(a) (a * 0.017453292519)
  </code></pre>
  
  <p>instead of inline functions.  Please excuse the newbie question, but what is so evil about macros in this case?</p>