default values for attributive parameters

Are default values supported for attributive parameters in an argument list?

I wish to convert these 2 subroutines to perl6:

sub foo {
  my $self = shift;

  $self->{foo} = defined $_[0] ? shift : undef;
}

sub bar {
  my $self = shift;

  $self->{bar} = defined $_[0] ? shift : $DEFAULT;
}

Is this correct?

method foo (?$.foo = undef) {};

method bar (?$.bar = $DEFAULT) {};


Thanks,
Carl

• default values for attributive parameters by Carl Franks
• Re: default values for attributive parameters by Juerd