move vtable test to math test

Author: qianxichen233

tests/unit-tests/math_tests/deterministic/vtable.c

@@ -0,0 +1,95 @@
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define EPS 1e-6
+
+typedef struct ShapeVTable {
+    double (*area)(void *self);
+} ShapeVTable;
+
+typedef struct Shape {
+    const ShapeVTable *vtable;
+} Shape;
+
+typedef struct {
+    Shape base;
+    double width;
+    double height;
+} Rectangle;
+
+typedef struct {
+    Shape base;
+    double radius;
+} Circle;
+
+double rectangle_area(void *self) {
+    Rectangle *r = (Rectangle *)self;
+    return r->width * r->height;
+}
+
+double circle_area(void *self) {
+    Circle *c = (Circle *)self;
+    return M_PI * c->radius * c->radius;
+}
+
+ShapeVTable rectangle_vtable = { rectangle_area };
+ShapeVTable circle_vtable = { circle_area };
+
+Rectangle *create_rectangle(double width, double height) {
+    Rectangle *r = malloc(sizeof(Rectangle));
+    r->base.vtable = &rectangle_vtable;
+    r->width = width;
+    r->height = height;
+    return r;
+}
+
+Circle *create_circle(double radius) {
+    Circle *c = malloc(sizeof(Circle));
+    c->base.vtable = &circle_vtable;
+    c->radius = radius;
+    return c;
+}
+
+double shape_area(Shape *shape) {
+    return shape->vtable->area(shape);
+}
+
+int main(void) {
+    Rectangle *rect = create_rectangle(3.0, 4.0);
+    Circle *circ = create_circle(2.5);
+
+    if (rect->base.vtable->area != rectangle_area) {
+        fprintf(stderr, "vtable test failed: rectangle vtable does not dispatch to rectangle_area\n");
+        free(rect);
+        free(circ);
+        return 1;
+    }
+    if (circ->base.vtable->area != circle_area) {
+        fprintf(stderr, "vtable test failed: circle vtable does not dispatch to circle_area\n");
+        free(rect);
+        free(circ);
+        return 1;
+    }
+
+    double rect_area = shape_area((Shape *)rect);
+    double circ_area = shape_area((Shape *)circ);
+
+    if (fabs(rect_area - 12.0) > EPS) {
+        fprintf(stderr, "vtable test failed: rectangle area mismatch\n");
+        free(rect);
+        free(circ);
+        return 1;
+    }
+    double expected_circ = M_PI * 2.5 * 2.5;
+    if (fabs(circ_area - expected_circ) > EPS) {
+        fprintf(stderr, "vtable test failed: circle area mismatch\n");
+        free(rect);
+        free(circ);
+        return 1;
+    }
+
+    free(rect);
+    free(circ);
+    return 0;
+}