gistfile1.pp

# using parenthesis hash style
class foo (
  $servername = $::fqdn,
  $port = 80,
  $ssl = false,
  $extra_opts={},
) {
  apache::vhost { $servername: ($extra_opts + {
      port => $port,
      ssl  => $ssl,
    })
  }
}

# using * =>
class foo (
  $servername = $::fqdn,
  $port = 80,
  $ssl = false,
  $extra_opts={},
) {
  apache::vhost { $servername:
    port => $port,
    ssl  => $ssl,
    *    => $extra_opts,
  }
}