As the thread here on PM and the two CPAN modules (written by notable Perl people) suggests, this is not as easy as it looks. I think the best way to get it right each time is to find an approach that always acts as "expected", and then put it in a module. I trust a module to be more consistent than me when faced with a repeated problem. :-)

Regarding your suggestions; it fails to behave like I would expect when it is inherited (and upon object destruction, but to be fair you do not have a constructor). 

{
    package Foo;

    sub can {
        my $self = shift;
        my $method = shift;
        return sub { print __PACKAGE__ . ": autoloaded $method\n" };
    }

    sub AUTOLOAD {
        my $code = $_[0]->can(our($AUTOLOAD) =~ /.*::(.*)/s);
        goto &$code;
    }
}
{
    package Bar;
    our @ISA = Foo::;

    sub new { bless {} => shift }

    sub bar { print __PACKAGE__ . ": bar\n" }
}

my $o = Bar::->new;

my $m = $o->can('bar');
$o->$m;

$o->bar;

__END__
Foo: autoloaded bar
Bar: bar
Foo: autoloaded DESTROY

[download]
In my solution outlined in the root node I handle it by moving the logic that generates the autoloaded subroutine reference to a common routine that both AUTOLOAD and can use. Then I see if UNIVERSAL::can returns anything. If it does it means that AUTOLOAD will not be invoked for $o->bar, so the return value of UNIVERSAL::can should be used instead. (This of course assumes that UNIVERSAL::can is not overloaded to do something else.)

The remaining logic in the root node is to handle when you use AUTOLOAD in a child class and the parent class also uses AUTOLOAD. This is even rarer, but it is still possible. As you say, it is important to trust a module to handle all edge cases so that you don't end up spending your evening debugging due to the module.

lodin

In reply to Re^4: A working strategy to handle AUTOLOAD, can(), and (multiple) inheritance without touching UNIVERSAL? by lodin
in thread A working strategy to handle AUTOLOAD, can(), and (multiple) inheritance without touching UNIVERSAL? by lodin

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