DB<1> @a = c..d

  DB<2> @h{a..d}=1..4

  DB<3> $h_ref = \%h

  DB<4> x $h_ref        # dump all
0  HASH(0x3531868)
   'a' => 1
   'b' => 2
   'c' => 3
   'd' => 4
  DB<5> x @h{@a}
0  3
1  4
  DB<6> x @{$h_ref}{@a} # play it safe
0  3
1  4
  DB<7> x @$h_ref{@a}   # brackets not needed b/c precedence already respected 
0  3
1  4
  DB<8>