use Benchmark qw (timethese);

timethese(10, {"regular" => \&regular, "reference" => \&reference});

sub regular {
	my %hash;
	for my $i (1 .. 100000) {
		$hash{$i} = $i;	
	}
	helper(\%hash);
}

sub reference {
	my $hash;
	for my $i (1 .. 100000) {
		$hash->{$i} = $i;	
	}
	helper($hash);
}

sub helper {
	my $hash = shift;
}