+
+ /**
+ * [subtree_elements(n)] returns the number of element nodes below [n]
+ * Runs in O(attribute_ids->size()+3)
+ */
+ inline uint32_t subtree_elements(node_t) const;
+
+ /**
+ * [num_children(n)] returns the number of child nodes of [n]
+ * (both text and elements, and including a fake <@> node if
+ * present).
+ * Runs in O(1) (?)
+ */