#!/usr/bin/perl
use strict;
use warnings;
use feature qw{ say };

{   package MyScalar;
    use Tie::Scalar;
    use parent -norequire => 'Tie::StdScalar' ;

    sub FETCH { warn 'f'; $_[0]->SUPER::FETCH(@_[1..$#_]) }
    sub STORE { warn "s$_[1]"; $_[0]->SUPER::STORE(@_[1..$#_]) }
}

tie my $s, 'MyScalar', 5;
say $s, $s = 4;
say "" . $s, $s = 3;