实测发现还是不行了，container_of再强大，也无法推断出这个呀。

library/circle.c

@@ -1,21 +1,21 @@
 
 #include "circle.h"
 
-double circle_area(void *self, void *parent)
+double circle_area(void *self)
 {
     double area = 0;
-    struct _circle *pthis = (struct _circle *)parent;
-    area = pthis->shape->vtb.area(self, NULL);
+    struct _circle *pthis = container_of(self, struct _circle, me);
+    area = pthis->shape->vtb.area(pthis);
     return area;
 }
 
-void circle_draw(void *self, void *parent)
+void circle_draw(void *self)
 {
-    struct _circle *pthis = (struct _circle *)parent;
-    pthis->shape->vtb.draw(self, NULL);
+    struct _circle *pthis = container_of(self, struct _circle, me);
+    pthis->shape->vtb.draw(pthis);
 }
 
-double _circle_area(void *self, void *parent)
+double _circle_area(void *self)
 {
     struct _circle *pthis = (struct _circle *)self;
     double area = 3.14 * pthis->radius * pthis->radius;
@@ -32,8 +32,8 @@ struct _circle *circle_new(double radius)
 {
     // super
     static struct _virtual_table vtb = {
-        .area = (double (*)(void *self, void *parent))_circle_area,
-        .draw = (void (*)(void *self, void *parent))_circle_draw,
+        .area = (double (*)(void *self))_circle_area,
+        .draw = (void (*)(void *self))_circle_draw,
     };
 
     struct _shape *shape = shape_new();
@@ -49,6 +49,7 @@ struct _circle *circle_new(double radius)
     {
         return NULL;
     }
+    circle->me = circle;
     circle->radius = radius;
     // set parent
     circle->shape = shape;

library/circle.h

@@ -7,7 +7,7 @@
 
 struct _circle
 {
-    int invalid;
+    struct _circle *me;
 
     // super
     struct _shape *shape;
@@ -22,7 +22,7 @@ struct _circle
 
 struct _circle *circle_new(double radius);
 
-double circle_area(void *self, void *parent);
-void circle_draw(void *self, void *parent);
+double circle_area(void *self);
+void circle_draw(void *self);
 
 #endif

library/copper.c

@@ -27,8 +27,8 @@ struct _copper_cash *copper_cash_new(double width, double height, double radius)
 {
     // super
     static struct _virtual_table vtb = {
-        .area = (double (*)(void *self, void *parent))copper_cash_area,
-        .draw = (void (*)(void *self, void *parent))copper_cash_draw,
+        .area = (double (*)(void *self))copper_cash_area,
+        .draw = (void (*)(void *self))copper_cash_draw,
     };
 
     struct _shape *shape = shape_new();
@@ -58,7 +58,7 @@ struct _copper_cash *copper_cash_new(double width, double height, double radius)
     {
         return NULL;
     }
-    cc->self = cc;
+    cc->me = cc;
 
     cc->price = 100;
     // set parent

library/copper.h

@@ -9,7 +9,7 @@
 
 struct _copper_cash
 {
-    struct _copper_cash *self;
+    struct _copper_cash *me;
 
     struct _shape *shape;
     struct _rect *rect;

library/rect.c

@@ -1,24 +1,21 @@
 
 #include "rect.h"
 
-double rect_area(void *self, void *parent)
+double rect_area(void *self)
 {
     double area = 0;
-    struct _rect *pthis = (struct _rect *)parent;
-    area = pthis->shape->vtb.area(self, NULL);
+    struct _rect *pthis = container_of(self, struct _rect, me);
+    area = pthis->shape->vtb.area(pthis);
     return area;
 }
 
-void rect_draw(void *self, void *parent)
+void rect_draw(void *self)
 {
-    // struct _rect *pthis = (struct _rect *)parent;
-    // pthis->shape->vtb.draw(self, NULL);
-
-    struct _rect *pthis = container_of(parent, struct _rect, self);
-    pthis->shape->vtb.draw(pthis, NULL);
+    struct _rect *pthis = container_of(self, struct _rect, me);
+    pthis->shape->vtb.draw(pthis);
 }
 
-double _rect_area(void *self, void *parent)
+double _rect_area(void *self)
 {
     struct _rect *pthis = (struct _rect *)self;
     double area = pthis->width * pthis->height;
@@ -27,7 +24,7 @@ double _rect_area(void *self, void *parent)
     return area;
 }
 
-void _rect_draw(void *self, void *parent)
+void _rect_draw(void *self)
 {
     printf("rect draw\n");
 }
@@ -36,8 +33,8 @@ struct _rect *rect_new(double width, double height)
 {
     // super
     static struct _virtual_table vtb = {
-        .area = (double (*)(void *self, void *parent))_rect_area,
-        .draw = (void (*)(void *self, void *parent))_rect_draw,
+        .area = (double (*)(void *self))_rect_area,
+        .draw = (void (*)(void *self))_rect_draw,
     };
 
     struct _shape *shape = shape_new();
@@ -53,7 +50,7 @@ struct _rect *rect_new(double width, double height)
     {
         return NULL;
     }
-    rect->self = rect;
+    rect->me = rect;
 
     rect->width = width;
     rect->height = height;

library/rect.h

@@ -8,7 +8,7 @@
 struct _rect
 {
     // int invalid;
-    struct _rect *self;    
+    struct _rect *me;    
 
     // super
     struct _shape *shape;
@@ -19,7 +19,7 @@ struct _rect
 
 struct _rect *rect_new(double width, double height);
 
-double rect_area(void *self, void *parent);
-void rect_draw(void *self, void *parent);
+double rect_area(void *self);
+void rect_draw(void *self);
 
 #endif

library/shape.c

@@ -1,12 +1,12 @@
 
 #include "shape.h"
 
-double virtual_area(void *self, void *parent)
+double virtual_area(void *self)
 {
     ASSERT_CALL_VIRTUAL_METHOD();
 }
 
-void virtual_draw(void *self, void *parent)
+void virtual_draw(void *self)
 {
     ASSERT_CALL_VIRTUAL_METHOD();
 }
@@ -25,26 +25,26 @@ struct _virtual_table *virtual_new(void)
 
 
 
-double shape_area(void *self, void *parent)
+double shape_area(void *self)
 {
     double area = 0;
-    struct _shape *pthis = (struct _shape *)parent;
-    area = pthis->vtb.area(self, NULL);
+    struct _shape *pthis = container_of(self, struct _shape, me);
+    area = pthis->vtb.area(pthis);
     return area;
 }
 
-void shape_draw(void *self, void *parent)
+void shape_draw(void *self)
 {
-    struct _shape *pthis = (struct _shape *)parent;
-    pthis->vtb.draw(self, NULL);
+    struct _shape *pthis = container_of(self, struct _shape, me);
+    pthis->vtb.draw(pthis);
 }
 
-PRIVATE double _shape_area(void *self, void *parent)
+PRIVATE double _shape_area(void *self)
 {
     ASSERT_CALL_VIRTUAL_METHOD();
 }
 
-PRIVATE void _shape_draw(void *self, void *parent)
+PRIVATE void _shape_draw(void *self)
 {
     ASSERT_CALL_VIRTUAL_METHOD();
 }
@@ -56,11 +56,11 @@ struct _shape *shape_new(void)
     {
         return NULL;
     }
-    shape->self = shape;
+    shape->me = shape;
 
     static struct _virtual_table vtb = {
-        .area = (double (*)(void *self, void *parent))_shape_area, 
-        .draw = (void (*)(void *self, void *parent))_shape_draw
+        .area = (double (*)(void *self))_shape_area, 
+        .draw = (void (*)(void *self))_shape_draw
     };
     shape->vtb = vtb;
     return shape;

library/shape.h

@@ -11,13 +11,13 @@
 
 struct _virtual_table
 {
-    VIRTUAL double (*area)(void *self, void *parent);
-    VIRTUAL void (*draw)(void *self, void *parent);
+    VIRTUAL double (*area)(void *self);
+    VIRTUAL void (*draw)(void *self);
 };
 
 struct _shape
 {
-    struct _shape *self;
+    struct _shape *me;
     
     struct _virtual_table vtb;
 };
@@ -25,8 +25,8 @@ struct _shape
 
 struct _shape *shape_new(void);
 
-double shape_area(void *self, void *parent);
-void shape_draw(void *self, void *parent);
+double shape_area(void *self);
+void shape_draw(void *self);
 
 #endif
 

src/main.c

@@ -7,20 +7,21 @@
 int main(int argc, char *argv[])
 {
     struct _rect *rect = rect_new(4, 5);
-    rect_area(rect, rect);
-    rect_draw(rect, rect);
+    rect_area(rect);
+    rect_draw(rect);
 
-    struct _circle *circle = circle_new(3);
-    circle_area(circle, circle);
-    circle_draw(circle, circle);
+    struct _circle *circle = circle_new(2);
+    circle_area(circle);
+    circle_draw(circle);
 
     printf("----- rect & circle -----\n");
-    shape_area(rect, rect->shape);
-    shape_draw(rect, rect->shape);
+    shape_area(rect->shape);
+    shape_draw(rect->shape);
 
-    shape_area(circle, circle->shape);
-    shape_draw(circle, circle->shape);
+    shape_area(circle->shape);
+    shape_draw(circle->shape);
 
+#if 0
     printf("----- [2] rect & circle -----\n");
     struct _rect *rect2 = (struct _rect *)rect_new(2, 3);
     shape_area(rect2, rect2->shape);
@@ -46,6 +47,6 @@ int main(int argc, char *argv[])
 
     circle_area(cc, cc->circle);
     circle_draw(cc, cc->circle);
-
+#endif
     return 0;
 }