[GRASS-dev] Howto use a Python function as error handler in libgis

[Glynn Clements]

Sören Gebbert wrote:

> Dear developers,
> i am trying to register a Python function as error handler callback
> using ctypes in libgis.
> I use this code in the temporal framework:
> 
> 
> {{{
> def error_handler(data):
>     pass
> 
> CALLBACK = CFUNCTYPE(None, c_void_p)

AFAICT, this needs to be:

	CALLBACK = CFUNCTYPE(c_void_p, c_void_p)

For callbacks, ctypesgen converts any return type which isn't a
primitive C type to c_void_p. And None isn't a primitive C type.

-- 
Glynn Clements <glynn at gclements.plus.com>