use v5.6.1;  #ActiveState build 626
use strict;
use warnings;

package Foo;

sub bar { print "Foo::bar has been called\n"; }

sub new
 {
 my $s= 0;
 return bless \$s, "Foo";
 }
 
package main;

*newFoo= \&Foo::new;

my $x1= new Foo::;
$x1->bar();   # OK

print "before:", join (' ', keys %main::), "\n";
delete $main::{"Foo::"};
print "after:", join (' ', keys %main::), "\n";
$x1->bar();   # still works!

my $x2= newFoo();  # works
$x2->bar(); # can't find "Foo"