package Foo;

sub whee {
  my $self = shift;
  print "$self says Wheee!\n";
}

sub make_whee {
  my ($instance, $func) = @_;
  $instance->$func();
}

make_whee(Foo->new(), "whee");

##</code><code>##

$class_method_ref = \&Foo::whee;
&$class_method_ref($foo_ob);

##</code><code>##

$foo_ob->bar("himom");
Foo::bar($foo_ob, "himom");
Foo->bar("himom");