[Vala] How to define inline callback functions in vapi

[Uwe Strempel <u strempel googlemail com>]

Hello,
How can I define inline declared callback functions in vapi files?
I have for example follwing native c-code functions:

class_new( void* (list_append)(void*,void*));

or 

class_new( void* (list_foreach)(void*,  void *(fnc)(void*,void*,void*) ,void*));



Thanks for help!

Best regards
Uwe Strempel