use strict ;
use warnings ;
use Storable qw( freeze thaw ) ;
use Data::Dumper ;

my $abc = "abc" ;
my @ar = ( \( substr( $abc, 0 ) ) ) ;
print "ar_0 = ${$ar[0]}\n" ;

my $def = "def" ;
my @ar2 = ( \( substr( $def, 0 ) ) ) ;
$def = undef ;
print "ar2_0 = ${$ar2[0]}\n" ;

$def = 'def' ;
print "ar2_0 = ${$ar2[0]}\n" ;

my $serialized1 = freeze \$abc ;
my $serialized2 = freeze \substr $def, 0 ;
$abc = 'ghi' ;
$def = 'jkl' ;
$abc = ${ thaw( $serialized1 ) } ;
$def = ${ thaw( $serialized2 ) } ;
print "thaw abc = $abc\n" ;
print "thaw def = $def\n" ;

my $xyz = "xyz" ;
my %xyz = ( _xyz => \substr $xyz, 0 ) ;
my $ser_xyz = freeze \%xyz ;
$xyz = "uvw" ;
my %copyxyz = %{ thaw( $ser_xyz ) } ;
print Dumper( \%copyxyz ) ;

__END__
ar_0 = abc
Use of uninitialized value in concatenation (.) or string at test2.pl line 13.
ar2_0 =
ar2_0 = def
thaw abc = abc
Use of uninitialized value $def in concatenation (.) or string at test2.pl line 25.
thaw def =
$VAR1 = {
          '_xyz' => \undef
        };