Don't free data after the code is done.

The callback is valid only during the call to the method.

Generics and defining elements of containers and arrays.

Free data after the code is done.

The callback is valid until first called.

NULL is ok, both for passing and for returning.

Parameter points to an array of items.

This parameter is a 'user_data', for callbacks; many bindings can pass NULL here.

Parameter for returning results. Default is transfer full.

Override the parsed C type with given type

Free data container after the code is done.