How to store array cookie in laravel 5.4?

I have this function in laravel 5.4 but I get error.

$cart[$product->id] = $quantity;
var_dump($cart);
return redirect('catalogs')->withCookie(cookie()->forever('cart', $cart));

var_dump($cart) contains this:

array(1) { [1]=> string(1) "1" }

Error warning:

Method Symfony\Component\HttpFoundation\Cookie::__toString() must not throw an exception, caught ErrorException: Array to string conversion

If I passed just string value (not array), it success. If there any way to store array cookie in Laravel?

Thank you.