use Carp qw( croak );

use Inline C => <<'__EOS__';

SV* _newRV(UV addr) {
   return newRV((SV*)addr);
}

__EOS__

sub destringify_ref {
   $_[0] =~ /\(([^()]*)\)/
      or croak("Invalid input");

   return _newRV(hex($1));
}

my %hash = ( a => 2, b => 3 );
my $ref = \%hash;
$ref = "$ref";
$ref = destringify_ref($ref);