#!/usr/bin/env perl
use warnings;
use strict;

use Foo;
use feature 'signatures';

foo(9,10);

sub foo($x,$y) {
	print $x+$y,"\n";
}

##</code><code>##

#!perl
package Foo;
use warnings;
use strict;

sub import {
	warnings->unimport('experimental::signatures')
		if $] >= 5.020;
}

1;

##</code><code>##

#!perl
package Foo;
use warnings;
use strict;

use parent 'Exporter';

sub import {
	warnings->unimport('experimental::signatures')
		if $] >= 5.020;
	__PACKAGE__->export_to_level(1, @_);
}

1;