Putting pages into a WordPress RSS feed

Every once in a while I want to put pages into an RSS feed on a self-hosted WordPress site. When I do this, I prefer to have a separate RSS feed for pages.
Here’s the system I use for this. Here’s the RSS for pages code on GitHub.
This is a nice way to add some kinds of client pages to the Pink Sheep Hub, but it’s also a nice way to keep an archive of pages if needed.
add_action( 'pre_get_posts', 't5_pages_in_feed' );
/**
* Set post type to 'page' if it was requested.
*
* @param object $query
* @return void
*/
function t5_pages_in_feed( &$query )
{
if ( isset ( $_GET['post_type'] ) && $_GET['post_type'] === 'page' && is_feed() )
{
$query->set( 'post_type', 'page' );
}
}
The feed show up at www.domaindotcom/feed/?post_type=page