#!

use Data::Dumper;
use strict;
use warnings;

sub f {                                            # (0)
    # 
     };

my $str; 
my $ref=[1,2];
print Data::Dumper->Dump([\$ref],[qw(*ref)]);  # (1)
$str=''.$ref;                                  
print Data::Dumper->Dump([\$str],[qw(*str)]);
# what do I need to do to $str so that (2) dump the original data structure
my $newref=f($str);
print Data::Dumper->Dump([\$newref],[qw(*newref)]);# (2)