c++ - 将类指针转换为空指针

Question

我怎样才能将类指针转换为像 void* 这样的通用指针？就像这个代码有效吗？

class CFoo
{
   int a;
public:
   CFoo():a(1){}
   ~CFoo(){}
   getNum(){return a;}
};

void tfunc(void* data)
{
    CFoo* foo = static_cast<CFoo*>(data);
    std::cout << "Number: " << foo->getNum();
    delete foo;
}

int main()
{
   CFoo* foo = new CFoo;
   void* dt = static_cast<void*>(foo);
   tfunc(dt); // or tfunc(static_cast<void*>(food));

   return 0;
}