+/**
+ * Get the key length of the current element.
+ *
+ * @param iter
+ * The hash table iterator.
+ * @return
+ * The current element key length, or 0 if the iterator points to an
+ * invalid element.
+ */
+size_t
+ec_htable_iter_get_key_len(const struct ec_htable_elt_ref *iter);
+