How do I specify the structure type returned from a C library?

[NotFound]

> I get a return from function.
> But how do I specify that it is an UnManagedStruct of my type?
> I failed to tie my returned pointer to a structire of given geometry.
>
> I tried
>        setprop obj_struct, "_struct", returned_obj
> and tried different combinations - I get different errors, "Missing struct initializer" or something like that,

The vtable function set_pmc looks like it must do the job. Try: set
returned_obj, obj_struct

-- 
Salu2