use strict;
use warnings;
use 5.10.0;


package Tie::Alias;
require Tie::Scalar;
our @ISA = qw(Tie::Scalar);
use Data::Dump qw/pp dd/;





sub FETCH {
    #pp \@_;
    my $obj =shift;
    return ${$obj->{alias}};
}

sub STORE {
    #pp \@_;
    my $obj = shift;
    ${$obj->{alias}} = $_[0];
}

sub TIESCALAR {
    #pp \@_;

    my $class = shift;
    my $alias = \ shift;

    my $obj = bless {alias => $alias}, $class;
    return $obj;
}




package main;

my $h={};

my $y;

tie $h->{y},'Tie::Alias', $y;

$y=666;

say $h->{y};

$y=42;

say $h->{y};

$h->{y}=123;

say $y;

my $g={};

tie $g->{y},'Tie::Alias', $y;

say $g->{y};

$h->{y}=999;

say "$h->{y},$g->{y},$y";

$h->{x}="whatever";

say "$h->{x},$g->{x}";