{
  package MyTH;

  use Tie::Hash;
  @ISA = qw( Tie::StdHash );

  sub FETCH { return $_[0]->{$_[1]} }
}

use Devel::Peek;

tie my %h, "MyTH";
$h{foo} = 1;

Dump($h{foo}) for 1 .. 3;

__output__

SV = PVMG(0x811a810) at 0x811f4a4
  REFCNT = 1
  FLAGS = (TEMP,GMG,SMG,RMG)
  IV = 0
  NV = 0
  PV = 0
  MAGIC = 0x8103ab8
  ...
SV = PVMG(0x811a810) at 0x811f4a4
  REFCNT = 1
  FLAGS = (TEMP,GMG,SMG,RMG)
  IV = 0
  NV = 0
  PV = 0
  MAGIC = 0x8104480
  ...
SV = PVMG(0x811a810) at 0x811f4a4
  REFCNT = 1
  FLAGS = (TEMP,GMG,SMG,RMG)
  IV = 0
  NV = 0
  PV = 0
  MAGIC = 0x8104480
  ...