Exclude Custom Post Types from RSS Feeds

PHP
1

Hello everyone,

The following code will exclude 1 category from the RSS feed.


function myFeedExcluder($query) {
 if ($query->is_feed) {
   $query->set('cat','-12');
 }
return $query;
}

add_filter('pre_get_posts','myFeedExcluder');

I want to modify this code to exclude 8 custom post types that i am using… How can i do this?

Will this make my site slower?

many thanks,
Andy