[Vala] Variable sized structs and vapi files

[Jan-Jaap van der Geer <jjvdgeer inbox com>]

I wonder how to "vapify" a struct that has a variable part at the
end, such as the wimp_menu below (somewhat simplyfied):

struct wimp_menu_entry
   {  wimp_menu_flags menu_flags;
      wimp_menu *sub_menu;
   };

#define wimp_MENU_MEMBERS \
   int width; \
   int height;

struct wimp_menu
   {  wimp_MENU_MEMBERS
      wimp_menu_entry entries [UNKNOWN];
   };

UNKNOWN is defined to be 1, but the intended structure can be any
length, dependent on what is apropriate. It is actually recommended
to use a macro for defining the structure:

#define wimp_MENU(N) \
   struct \
      {  wimp_MENU_MEMBERS \
         wimp_menu_entry entries [N]; \
      }

I wonder how to do this. Somehow Vala needs to know how to allocate
and free the memory for these structures, so I suppose it somehow
needs to be told - but I do not know how.

Any ideas?

Related: Is there documentation about this? If so where can I find
that?

Cheers,
Jan-Jaap