title: C++ preprocessor __VA_ARGS__ number of arguments
body: <p>Simple question for which I could not find answer on the net. In variadic argument macros, how to find the number of arguments?  I am okay with boost preprocessor, if it has the solution.</p>
  
  <p>If it makes a difference, I am trying to convert variable number of macro arguments to boost preprocessor sequence, list, or array for further reprocessing.</p>