title: Is there a good general method for debugging C++ macros?
body: <p>In general, I occasionally have a chain of nested macros with a few preprocessor conditional elements in their definitions.  These can be painful to debug since it's hard to directly see the actual code being executed.</p>
  
  <p>A while ago I vaguely remember finding a compiler (gcc) flag to expand them, but I had trouble getting this to work in practice.</p>