my @w = () = 1;
  print "[", @w, "]\n";               # prints: []

  my @x = (undef) = 2;
  print "[", @x, "]\n";               # prints: [2]

  my @y = (undef) = (3,4);
  print "[", @y, "]\n";               # prints: [3]

  my @z = (undef, undef) = (5,6);
  print "[", @z, "]\n";               # prints: [56]

  my $temp;
  my @z = (undef, $temp, undef) = (7,8,9);
  print "[", @z, "]\n";               # prints: [789]

##</code><code>##

  my $count = () = "abacadaeafag" =~ /a/g;
  my @empty = () = "abacadaeafag" =~ /a/g;
  print "[", $count, "]\n";           # prints: [6]
  print "[", @empty, "]\n";           # prints: []

##</code><code>##

  $_ = "abacadaeafag";                # or whatever
  if ( scalar( () = /a/g ) > 7 ) {    # more than 7 'hits'?
     # do something...
  }