+/*
+ * NAME
+ * c_avl_size
+ *
+ * DESCRIPTION
+ * Return the size (number of nodes) of the specified tree.
+ *
+ * PARAMETERS
+ * `t' AVL-tree to get the size of.
+ *
+ * RETURN VALUE
+ * Number of nodes in the tree, 0 if the tree is empty or NULL.
+ */
+int c_avl_size (c_avl_tree_t *t);
+