use if $/ = "\n", 5.012 => qw( say );

--output:--
Can't locate 5.012.pm in @INC (@INC contains: /Users/7stud/perl5/perlbrew/perls/perl-5.16.0/lib/site_perl/5.16.0/darwin-2level /Users/7stud/perl5/perlbrew/perls/perl-5.16.0/lib/site_perl/5.16.0 /Users/7stud/perl5/perlbrew/perls/perl-5.16.0/lib/5.16.0/darwin-2level /Users/7stud/perl5/perlbrew/perls/perl-5.16.0/lib/5.16.0 .) at /Users/7stud/perl5/perlbrew/perls/perl-5.16.0/lib/5.16.0/if.pm line 13.
BEGIN failed--compilation aborted at 2.pl line 1.

##</code><code>##

our $verbose = 1;
use if $verbose, 'strict';

$v = 'hello';

##</code><code>##


use strict;
use warnings;
#use 5.012;  #enables say()

use subs qw( say );

my $verbose = 1;  

sub say {
    if ($verbose) {
        print shift, " world\n";
    }
}

say 'hello';

--output:--
hello world