That way, headers can use the gesture type without having to include
gtkgesture.h
#define GTK_IS_GESTURE_CLASS(k) (G_TYPE_CHECK_CLASS_TYPE ((k), GTK_TYPE_GESTURE))
#define GTK_GESTURE_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), GTK_TYPE_GESTURE, GtkGestureClass))
-typedef struct _GtkGesture GtkGesture;
typedef struct _GtkGestureClass GtkGestureClass;
GDK_AVAILABLE_IN_ALL
typedef struct _GtkBuilder GtkBuilder;
typedef struct _GtkClipboard GtkClipboard;
typedef struct _GtkEventController GtkEventController;
+typedef struct _GtkGesture GtkGesture;
typedef struct _GtkRequisition GtkRequisition;
typedef struct _GtkSelectionData GtkSelectionData;
typedef struct _GtkSettings GtkSettings;