Displays or retrieves page title for post.

This is optimized for single.php template file for displaying the post title.

It does not support placing the separator after the title, but by leaving the
prefix parameter empty, you can set the title separator manually. The prefix
does not automatically place a space between the prefix, so if there should
be a space, the parameter value will need to have it at the end.

function single_post_title( $prefix = '', $display = true ) {
	$_post = get_queried_object();

	if ( ! isset( $_post->post_title ) ) {
		return;
	}

	/**
	 * Filters the page title for a single post.
	 *
	 * @since 0.71
	 *
	 * @param string  $_post_title The single post page title.
	 * @param WP_Post $_post       The current post.
	 */
	$title = apply_filters( 'single_post_title', $_post->post_title, $_post );
	if ( $display ) {
		echo $prefix . $title;
	} else {
		return $prefix . $title;
	}
}