gistfile1.txt

use v6;

class A does Positional {
    subset A::Value where { $_ ~~ /^<[a..z]>$/ }
    has @!a_values handles Positional;
    method new (*@values) { self.bless(a_values => @values) }
    submethod BUILD (:@!a_values) {}
}

my $o = A.new('foo', 'bar');

say $o.elems;
say $o.join(',');
say $o;