Small shape.c update.

1 files changed, 5 insertions, 7 deletions

diff --git a/examples/shape.c b/examples/shape.c
index 04aecaa1..d3534021 100644
--- a/examples/shape.c
+++ b/examples/shape.c
@@ -4,10 +4,8 @@
 #include <stdio.h>

 #include <stc/ccommon.h>

 

-#define c_self(s, T) \

-    T* self = (T *)(s); \

-    assert(&T##_api == (s)->api && \

-           &T##_api == self->base.api)

+#define c_dyn_ptr(T, s) \

+    (&T##_api == (s)->api ? (T*)(s) : (T*)0)

 

 #define c_vtable(Api, T) \

     c_static_assert(offsetof(T, base) == 0); \

@@ -66,7 +64,7 @@ Triangle* Triangle_new(Point a, Point b, Point c)
 

 static void Triangle_draw(const Shape* shape)

 {

-    const c_self(shape, Triangle);

+    const Triangle* self = c_dyn_ptr(Triangle, shape);

     printf("Triangle : (%g,%g), (%g,%g), (%g,%g)\n",

            self->p[0].x, self->p[0].y,

            self->p[1].x, self->p[1].y,

@@ -105,7 +103,7 @@ void Polygon_addPoint(Polygon* self, Point p)
 

 static void Polygon_drop(Shape* shape)

 {

-    c_self(shape, Polygon);

+    Polygon* self = c_dyn_ptr(Polygon, shape);

     printf("poly destructed\n");

     PointVec_drop(&self->points);

     Shape_drop(shape);

@@ -113,7 +111,7 @@ static void Polygon_drop(Shape* shape)
 

 static void Polygon_draw(const Shape* shape)

 {

-    const c_self(shape, Polygon);

+    const Polygon* self = c_dyn_ptr(Polygon, shape);

     printf("Polygon  :");

     c_foreach (i, PointVec, self->points)

         printf(" (%g,%g)", i.ref->x, i.ref->y);