#!/usr/bin/perl -w

use strict;
use Data::Dumper;

{
    package foo;
    use Tie::IxHash;
	use Data::Dumper;
    tie(my %h, 'Tie::IxHash', qw(one two three four));
    sub new { my %newh = %h; bless { val => \%newh } }
    sub val : lvalue  { my $r = \$_[0]->{val}{one}; $$r }
}

use Devel::Peek;
my $obj =  foo->new;
Dump( $obj->{val}->{one} );
#  dies here
$obj->val = "foo";
warn Dumper($obj);