package myblib;
sub foo { print +(caller(0))[3],"(@_)\n" }
1;

##</code><code>##

package vlog;
use myblib;
sub bar { print +(caller(0))[3],"(@_)\n" }
1;

##</code><code>##

# line 1 gen.pl
use vlog;
myblib::foo(1);
myblib->foo(2);

# foo();        # this would die - no foo() in main::
# bar();        # as would this

package myblib; # temporarily switch package
foo(3);
package main;   # switch back

@ISA = qw(myblib);
$a = bless do { \ my $x }, 'main';

$a->foo(4);      # method lookup finds foo() in myblib::

# shoehorn the foo() function into main:: - that's roughly
# what Exporter and 'use myblib qw(foo)' do

*foo = *myblib::foo;

foo(5);          # now found in main::
$a->foo(6);
__END__
myblib::foo(1)
myblib::foo(myblib 2)
myblib::foo(3)
myblib::foo(main=SCALAR(0x818c688) 4)
myblib::foo(5)
myblib::foo(main=SCALAR(0x818c688) 6)