package Foo;
sub foo { 'foo' }

package Bar;         # Bar inherits 'foo' from Foo
@ISA = qw(Foo);
sub bar { 'bar' }    # Bar defines 'bar'

package main;
use Class::CanBeA;
my @subclasses = @{Class::CanBeA::subclasses('Foo')};
foreach my $class (@subclasses) {
    print "$class is a subclass of Foo\n";
    foreach my $sub (qw(foo bar)) {
        if(!exists(&{$class.'::'.$sub}) && $class->can($sub)) {
            print $class.'::'.$sub." is inherited\n";
        }
    }
}