package Demo1;

use base qw/Exporter/;

$SUCCESS = 1;

BEGIN {
     use Exporter();
     @ISA = qw(Exporter);
     @EXPORT = qw( $SUCCESS )
}

1;

##</code><code>##

package Demo2;

sub import {
    ${[caller]->[0].'::'}{$_} = ${__PACKAGE__."::"}{$_}
        foreach grep { not /^(ISA|isa|BEGIN|import|Dumper)$/ } 
                      keys %{__PACKAGE__."::"};
}

use constant { 
    SUCCESS => 0,
};

1;

##</code><code>##


#!/usr/bin/perl

use strict;
use warnings;

use Demo1;
use Demo2;

print "SUCCESS: ", SUCCESS, "\n";
print "\$SUCCESS: $SUCCESS\n";

exit;

##</code><code>##

Bareword "SUCCESS" not allowed while "strict subs" in use at ./demo.pl line 9.
Execution of ./demo.pl aborted due to compilation errors.

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

use Demo2;
use Demo1;

print "SUCCESS: ", SUCCESS, "\n";
print "\$SUCCESS: $SUCCESS\n";

exit;

##</code><code>##

SUCCESS: 0
$SUCCESS: 1