DB<101> w @{[$z++]}

  DB<102> r
0
Watchpoint 0:	@{[$z++]} changed:
    old value:	'0'
    new value:	'1'
main::(tst.pl:12):	say $x++;
  DB<102> r
1
Watchpoint 0:	@{[$z++]} changed:
    old value:	'1'
    new value:	'2'
main::(tst.pl:13):	print $x++;