How to disable registration new users in Laravel

Laravel 5.7 introduced the following functionality:

Auth::routes(['register' => false]);

The currently possible options here are:

Auth::routes([
  'register' => false, // Registration Routes...
  'reset' => false, // Password Reset Routes...
  'verify' => false, // Email Verification Routes...
]);

For older Laravel versions just override showRegistrationForm() and register() methods in

• AuthController for Laravel 5.0 – 5.4
• Auth/RegisterController.php for Laravel 5.5

public function showRegistrationForm()
{
    return redirect('login');
}

public function register()
{

}