me data", even if the latter is more accurate,
      because it more closely corresponds to the way I believe C++ programmers think
      about macro programming.
    </p>
<p>
      The term 'emptiness' refers to no preprocessor data being passed to or returned
      from a macro. I have avoided the word 'nothing' because it has too vague a
      meaning.
    </p>
<p>
      The term 'data type' refers to the various preprocessor input types which VMD
      can parse and which are listed above, also includin