my $t;

class A {};
class B {};

sub a (A $a) {};
sub b (B $a) {};

multi sub c (A $a) {};
multi sub c (B $a) {};

for ^7 {
  my $iterations = ^10 ** $_;
  say $iterations.max ~ " calls";

  $t = now;
  for ^$iterations { $_ %% 2 ?? a(A) !! b(B) };
  say "regular: {now - $t}";

  $t = now;
  for ^$iterations { c($_ %% 2 ?? A !! B) };
  say "multi:   {now - $t}";
}