结构体中的void指针的使用

#include 
#include 

struct A{
	int a;
	void *pa;
};
struct B{
	int b;
	void *pb;
};
int main(){
	struct B b1;
	b1.b = 1;
	int cc = 23;
	b1.pb = &cc;
	printf("b1.b = %dtb1.pb = %dn",b1.b,*(int *)(b1.pb));
	//如下直接对void指针解引用是错误的
	//printf("b1.pb = %dn",*b1.pb);
    //指针结构体要分配空间才能使用
	struct A *a1 = (struct A*)malloc(sizeof(struct A));
	a1->a  = cc;
	a1->pa = &b1;
	printf("a1->a = %dt",a1->a);
	printf("a1->pa->b= %dn",((struct B *)a1->pa)->b);
	return 0;
}