How do I modify the 'more' link in a feed

Posted: - Source : stackoverflow

I use a function to modify the 'read more' link for posts.

function modify_read_more_link() {
return '<p class="read-more"><a href="' . get_permalink() . '">CONTINUE READING &raquo</a></p>';
add_filter( 'the_content_more_link', 'modify_read_more_link' );

I want to use different text for the feed, and wonder whether this can be done using a conditional if is_feed() tag?

(I don't know enough, and my experiments either don't work or halt page loads.)