cmpthese(10000, {
   'orig' => sub { foreach my $x ( 0..9, 'a'..'v', 'A'..'V' ) { $x = MyMod::MapChar($x); }},
   'new'  => sub { foreach my $x ( 0..9, 'a'..'v', 'A'..'V' ) { $x = MyMod::MapChar2($x); }},
   }
);