Optional Parameters with C++ Macros

None of the above examples (from Derek Ledbetter, David Sorkovsky, and Joe D) to count arguments with macros worked for me using Microsoft VCC 10. The __VA_ARGS__ argument is always considered as a single argument (token-izing it with ## or not), so the argument shifting in which those examples rely doesn't work.

So, short answer, as stated by many others above: no, you can't overload macros or use optional arguments on them.