There are a lot of methods which currently take a pointer and a DestroyNotify, and it would be very nice to be able to bind them as generic methods, and have the DestroyNotify be set automatically (obviating the need for exposing free methods--see bug #581075). In order to do this I think at least 4 CCode attributes are needed:

* Something to hide the GType argument that is currently generated.
* Something to hide the GBoxedCopyFunc argument that is currently generated.
* Something to mark the position of the DestroyNotify argument (not unlike array_length_pos)
* Something to hide / show the DestroyNotify argument (not unlike array_length).

It might also be good to have something to mark the position of the GType and GBoxedCopyFunc arguments.

It would also be great to have a way to use the metadata files to mark the relevant functions for generated bindings.

For a good example of where this would be very useful, please look at Object.set_data_full(), which currenly looks like:

public void set_data_full (string key, void* data, DestroyNotify? destroy);

But something like this would be much easier to use:

public void set_data_full<T> (string key, [CCode (...)] T data);