{
    package Foo;
    use MyBase -base, is => 'foo';
}
{
    package Bar;
    use MyBase -base, is => 'bar';
}

printf "%-9s %s %s\n", $_, $_->is_foo, $_->is_bar
    for Foo::, Bar::;

__END__
Foo       1 0
Bar       0 1