use Benchmark 'timethese';

$x = int (1_000_000 * rand 1_000_000);

timethese(-5, {
  multiple    => sub { $x =~ /(\d)*(\d)/ },
  backtrack_c => sub { $x =~ /(\d*)(\d)/ },
  backtrack   => sub { $x =~ /\d*(\d)/   },
  opt         => sub { $x =~ /(\d)$/     },
  mod         => sub { $x % 10           },
});