use v5.14;
use strict;
use warnings;

package Test {
  sub new { my $scalar = $_[1]; bless \$scalar, shift }
  sub value { ${ $_[0] } = $_[1] if @_ > 1; ${ $_[0] } }
}

package CallerHash {
  sub TIEHASH {
    return bless \$_[1], $_[0];
  }

  sub FETCH {
    my $obj = ${ +shift };
    my $method = shift;
    return $obj->$method();
  }

  sub STORE {
    my $obj = ${ +shift };
    my $method = shift;
    $obj->$method(@_);
  }
}

my $obj = Test->new(4);

tie my %objAsHash, CallerHash => $obj;

say "$objAsHash{value}";
$objAsHash{value} = 42;
say "$objAsHash{value}";

say $$obj;