- 'tie' => sub { my ($x, $y) = map @a[rand @a], 1 .. 2; my $a = $t{$x}; $t{$y} = $a },
- 'v::m' => sub { my ($x, $y) = map @a[rand @a], 1 .. 2; my $a = $v{$x}; $v{$y} = $a }
+ 'tie' => sub { my ($x, $y) = map @a[$x++ % @a], 1 .. 2; my $a = $t{$x}; $t{$y} = $a },
+ 'v::m' => sub { my ($x, $y) = map @a[$x++ % @a], 1 .. 2; my $a = $v{$x}; $v{$y} = $a }