@__PACKAGE__::ISA means @ISA in the package "__PACKAGE__", not the current package. 

use strict;
use warnings;

use base 'CGI';

print "@main::ISA\n";  # CGI

our @ISA;
print "@ISA\n";        # CGI

my @ourISA = do { no strict 'refs'; @{__PACKAGE__ . '::ISA'} };
print "@ourISA\n";     # CGI

[download]

I wouldn't use base. It's even been obsoleted with parent in newer versions of Perl.

In reply to Re: Where is the @ISA array? by ikegami
in thread Where is the @ISA array? by metaperl

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