Checking if WordPress post has more

WordPress offers the has_excerpt() method to determine if you create a separate excerpt on a post, but does not seem to have a built in function to ask if it uses the special comment <!--more--> for an excerpt coming from the beginning of the post content. I wanted to ask this question in my theme so I could show a more link with my own markup only if there is actually more. A Stack Exchange answer helped me out. I created a function, like:

function doesPostHaveMore($post = null){
        return true;
        $post = get_post($post);
    return is_object($post) && strpos($post->post_content, '<!--more-->') !== false;

The function could be added in functions.php. To use, within a post template:

<?php if(!is_singular() && doesPostHaveMore()){ ?>
<a class="more-link" href="<?=the_permalink()?>"><?=__('Continue reading')?> <span class="sro">"<?=get_the_title()?>"</span></a>
<?php } ?>