Make an object a composite object of another.
The class of comp_obj must be part of the extensions of the class of the parent. It isn't possible to attach more then 1 composite of the same class. This function also sets the parent of comp_obj to parent.
See Efl.Object.composite_detach, Efl.Object.composite_part_is.
Since 1.22
composite_attach @beta { params { @in comp_obj: Efl.Object; } return: bool; }
Eina_Bool efl_composite_attach(Eo *obj, Efl_Object *comp_obj);