------------------------------------------------------------ Return Marshallers: Return a value, don't have user data ------------------------------------------------------------
type Handler_Proxy is access function
(Widget : access Widget_Type'Class;
Params : Glib.Values.GValues;
Cb : General_Handler) return Return_Type;
type Marshaller is record
Func : General_Handler;
Proxy : Handler_Proxy;
end record;
User callback
Handler_Proxy for this callback
type Return_Type is (<>);
type Widget_Type is new Glib.Object.GObject_Record with private;