Magic [Slightly Off-Topic... please point me to documentation]Garrett Goebel
wrote:
> I was recently bit by overloading magic in the Class::Context
> generic constructor which the following code illustrates. If
> you return "another" reference to a scalar which was blessed,
> instead of the blessed reference, then you loose your magic.
> I'm trying to keep Class::Contract (which I'm maintaining for
> Damian) overload friendly... But Perl magic on my map is
> labelled "there be dragons".
>
Only blessed objects can be overloaded, not references. Only a class can
have overloading behaviour, and a plain reference belongs to no class, so it
should have no overloading behaviour. Contrast this use of \$key with having
[1,2,3]. Do you think this array reference should have any overloading
behaviour? Or else, try to define a method in package bar and try to call it
from $bar, like $bar->foo. Won't work either, you have to ${$bar}->foo.
Overloading should loose the magic in the same sense that the method should
not be called.
> package bar;
> @ISA = qw(foo);
> sub new { bless \my $key; \$key }
You return a reference to the object...
> package main;
> my ($bar, $baz);
> $bar = bar::->new();
> $baz = baz::->new();
>
> print "bar $bar\n";
> print "baz $baz\n";
Try printing $$bar, it will work...
- Branden
