package RememberingSet;

use Moo;

has '_count' => (is => 'ro', default => sub { {  } });

extends 'Set';
no Moo;

sub has {
    my ($self, $e) = @_;

    $self->_count->{ $e }++;
    $self->SUPER::has($e);
}

sub add {
    my ($self, $e) = @_;

    $self->_count->{ $e }++;
    $self->SUPER::add($e);
}

sub seen {
    my ($self, $e) = @_;

    exists $self->_count->{ $e }
      ? $self->_count->{ $e }
      : 0;
}

1;