如何在laravel5的join子句中使用raw查询？

use Illuminate\Support\Facades\DB;

$users = DB::table('users')
            ->select(DB::raw('users.id, users.name, orders.order_date'))
            ->join('orders', function ($join) {
                $join->on('users.id', '=', 'orders.user_id')
                     ->whereRaw('orders.order_date > CURDATE()');
            })
            ->get();