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.
Generics and defining elements of containers and arrays.
Parameter for input and for returning results. Default is transfer full.
NULL may be passed as the value in, out, in-out; or as a return value.
NULL may be passed instead of a pointer to a location.
The callback is valid only during the call to the method.
Exposed in C code, not necessarily available in other languages.
Free data after the code is done.
Don't free data after the code is done.
Override the parsed C type with given type.