I'm trying to take advantage of the MAIN suroutine to handle most all of my
routine command line arg handling. One idiom I use a lot is for the user
to choose only one of two args, but one must be chosen.
Reading S06, I don't yet see a way to do that without dropping back to
handling the @*ARGV array in the same way I am used to handling the @ARGV
array in Perl 5 (e.g., as each arg 1 or 2 is checked for in @ARGV, check if
the other has been entered already and inform the user accordingly; then,
after @ARGV is read, ensure one of the required args was found).
Am I wrong?