-typedef void *stat_create (const struct means *, struct pool *pool);
-
-typedef void stat_update (const struct means *, void *stat, double w, double x);
-
-typedef double stat_get (const struct means *, struct per_var_data *, void *aux);
-
+typedef void *stat_create (struct pool *pool);
+typedef void stat_update (void *stat, double w, double x);
+typedef double stat_get (const struct per_var_data *, void *aux);