The module is highly magical... I don't really understand it either but

use strict;
use warnings;
use IO::All;
use feature qw(say);

my $io = io('/home/vic');
say *$io->{_constructor};

my $io2 = IO::All->new();
$io2->dir('/home/vic/');
say *$io2->{_constructor};

__END__
CODE(0x16de930)
Use of uninitialized value in say at karl.pl line 14.
[download]

Seems to me the $io2 lacks the field _constructor simply because nothing sets it... so I don't know if it should even work.