package Foo;

class {
    attr qw( foo bar );
    method floober =>
        signature ( Int, Int ),
        body {
            ...
        };
};

##</code><code>##

sub class (&) {
    my ($sub) = @_;
    $sub->();

    # Do some book-keeping in the caller's namespace.
}

##</code><code>##

class 'Foo' is {
};

##</code><code>##

sub is (&) { return @_ }