Another way is to use a dualvar() (from Scalar::Util) for such a purpose:

    use Scalar::Util qw/dualvar/;
    my $x = dualvar(1,"0");

    $y = $x + 41;
    print "$y\n"; # 42

    print "Str \$x: $x\n";
    print "Num \$x: ", $x + 0, "\n";

    if($x + 0){print "\$x + 0 is true\n"}
    unless($x){print "\$x is false\n"}
    __END__

    prints:
        42
        Str $x: 0
        Num $x: 1
        $x + 0 is true
        $x is false
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