code quality: fix @var tags for nullable WP_Rewrite props

Author: justlevine

src/wp-includes/class-wp-rewrite.php

@@ -52,39 +52,39 @@ class WP_Rewrite {
 	 * Permalink structure for author archives.
 	 *
 	 * @since 1.5.0
-	 * @var string
+	 * @var ?string
 	 */
 	public $author_structure;
 
 	/**
 	 * Permalink structure for date archives.
 	 *
 	 * @since 1.5.0
-	 * @var string
+	 * @var ?string
 	 */
 	public $date_structure;
 
 	/**
 	 * Permalink structure for pages.
 	 *
 	 * @since 1.5.0
-	 * @var string
+	 * @var ?string
 	 */
 	public $page_structure;
 
 	/**
 	 * Base of the search permalink structure (example.com/$search_base/query).
 	 *
 	 * @since 1.5.0
-	 * @var string
+	 * @var ?string
 	 */
 	public $search_base = 'search';
 
 	/**
 	 * Permalink structure for searches.
 	 *
 	 * @since 1.5.0
-	 * @var string
+	 * @var ?string
 	 */
 	public $search_structure;
 
@@ -124,15 +124,15 @@ class WP_Rewrite {
 	 * Comments feed permalink structure.
 	 *
 	 * @since 1.5.0
-	 * @var string
+	 * @var ?string
 	 */
 	public $comment_feed_structure;
 
 	/**
 	 * Feed request permalink structure.
 	 *
 	 * @since 1.5.0
-	 * @var string
+	 * @var ?string
 	 */
 	public $feed_structure;