Hi Monks! In my script below I am attempting to use overload to perform a "$obj_a == $obj_b" comparison. This works fine if I overload a simple object. But in my app I want a cascading overload, where an object may not have the overload operator for '==' defined, but it's child object may have one. This is replicated below, with the child object being 'test' and the parent object being 'parent'. The output of this script is:

Comparing 4 and 4
x equals y
Comparing 4 and 4
nomethod(==) returning value '1'
x doesn't equal y

As you can see, the last call "$x == $y" where x and y are both in class 'parent' returns an empty string, which evaluates to false in bool context. Clearly, though, the call to nomethod() in the parent class returned the value '1', so why does it wind up being an empty string? Am I misunderstanding the usage of the overload.pm feature nomethod?

#!/usr/bin/perl

package test;

use strict;
use warnings;

use overload
    '==' => sub {
        my ($self, $other) = @_;
        print STDERR "Comparing $$self[0] and $$other[0]\n";
        return $self->[0] == $other->[0];
    };

sub new {
    my ($class, $num) = @_;

    return bless [ $num ], $class;
}

package parent;

use strict;
use warnings;

use overload
    nomethod => sub {
        my ($obj, $other, $inv, $meth) = @_;

        if (my $sub = overload::Method($obj->{test}, $meth)) {
            my $return = $sub->($obj->{test}, $other->{test}, $inv);
            print STDERR "nomethod($meth) returning " . (defined $retu
+rn ? "value '$return'" : 'undef') . "\n";
            return $return;
        }
    };

sub new {
    my $class = shift;

    my $self = {
        test => test->new(@_),
    };
    return bless $self, $class;
}

package main;

use strict;
use warnings;

my $x = test->new(4);
my $y = test->new(4);

print "x " .($x == $y ? "equals" : "doesn't equal"). " y\n";

$x = parent->new(4);
$y = parent->new(4);

print "x " .($x == $y ? "equals" : "doesn't equal"). " y\n";
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