fx.collections: update iterator semantics

fx.collections/test/hashtables.c

@@ -19,13 +19,13 @@ int main(void)
 		printf("no value\n");
 	}
 
-	fx_iterator *it = fx_hashtable_begin(ht);
+	const fx_iterator *it = fx_hashtable_begin(ht);
 	fx_foreach(val, it)
 	{
 		fx_hashtable_item *item = NULL;
-		fx_value_get_object(&val, &item);
+		fx_value_get_object(val, &item);
 		printf("item %p\n", item);
-		fx_value key, value;
+		const fx_value *key, *value;
 		key = fx_hashtable_item_get_key(item);
 		value = fx_hashtable_item_get_value(item);
 
@@ -34,10 +34,10 @@ int main(void)
 		fx_foreach(prop_val, prop_it)
 		{
 			fx_property *prop;
-			fx_value_get_object(&prop_val, &prop);
+			fx_value_get_object(prop_val, &prop);
 			printf("%s = ", fx_property_get_name(prop));
 			fx_value value = FX_VALUE_EMPTY;
-			fx_property_get_value(prop, &val, &value);
+			fx_property_get_value(prop, val, &value);
 			fx_value_to_string(&value, fx_stdout, NULL);
 			printf("\n");
 		}