+/**
+ * G_FILE_ATTRIBUTE_THUMBNAIL_IS_VALID:
+ *
+ * A key in the "thumbnail" namespace for checking whether the thumbnail is outdated.
+ * This attribute is %TRUE if the thumbnail is up-to-date with the file it represents,
+ * and %FALSE if the file has been modified since the thumbnail was generated.
+ *
+ * If %G_FILE_ATTRIBUTE_THUMBNAILING_FAILED is %TRUE and this attribute is %FALSE,
+ * it indicates that thumbnailing may be attempted again and may succeed.
+ *
+ * Corresponding #GFileAttributeType is %G_FILE_ATTRIBUTE_TYPE_BOOLEAN.
+ *
+ * Since: 2.40
+ */
+#define G_FILE_ATTRIBUTE_THUMBNAIL_IS_VALID "thumbnail::is-valid" /* boolean */