$ perl -wle'use overload q!""!=>sub{0},fallback=>1; $x=bless[0]; $y=bless[1];
print map @$_, sort { $b <=> $a or $b cmp $a } $x, $y;
print map @$_, reverse sort { $a <=> $b or $a cmp $b } $x, $y'
01
10