#       strict-demo.pl
#       =  Copyright 2011 Xiong Changnian <xiong@cpan.org>   =
#       = Free Software = Artistic License 2.0 = NO WARRANTY =

use strict;             # comment out to avoid errors

#----------------------------------------------------------------------------#
# Uncomment lines to force strict errors...

#    $x  = 5;                            # no strict 'vars'
#    print "$x\n";

#    my $subroutine  = factorial;        # no strict 'subs'
#    print $subroutine->(7), "\n";

#    our $dog;
#    my $pet     = 'dog';
#    ${ $pet }   = 'Rover';              # no strict 'refs'
#    print "$dog\n";

#----------------------------------------------------------------------------#
# Uncomment this whole section for a successful run...

#    my $x;                              # declare first
#    $x  = 5;                            # strict okay
#    print "$x\n";

#    my $subroutine  = \&factorial;      # strict okay
#    print $subroutine->(7), "\n";

#    our $dog;
#    my $pet     = \$dog;                # hard reference
#    ${ $pet }   = 'Rover';              # strict okay
#    print "$dog\n";

#----------------------------------------------------------------------------#

print "Done.\n";

sub factorial {
    my $in      = shift;
    my $out     = 1;

    for my $factor (2..$in) {
        $out        *= $factor;
    };

    return $out;
};

__END__