do {
   local @_;
   alias $_[0] = "first=";
   alias $_[1] = $var;
   alias $_[2] = " second=";
   my $anon = $var--;         # <-- Changes $var *and* $_[1]
   alias $_[3] = $anon;       #     since $_[1] is an alias
   alias $_[4] = "\n";        #     for $var.
   &print;
};