c++ - 虚拟析构函数在特定情况下的实际必要性

Question

C++03 5.3.5.3

In the first alternative (delete object), if the static type of the operand is different from its dynamic type, the static type shall be a base class of the operand’s dynamic type and the static type shall have a virtual destructor or the behavior is undefined.

这是理论。然而，这个问题是一个实际的问题。如果派生类不添加数据成员怎么办？

struct Base{
   //some members
   //no virtual functions, no virtual destructor
};
struct Derived:Base{
   //no more data members
   //possibly some more nonvirtual member functions
};

int main(){
     Base* p = new Derived;
     delete p; //UB according to the quote above
}

问题:是否存在任何现有的实现，这真的很危险？如果是这样，您能否描述一下在导致此代码崩溃/泄漏或其他情况的实现中如何实现内部结构？我求你相信，我发誓我无意依赖这种行为:)

Answer 1

一个示例是，如果您在 struct Derived 中提供自定义 operator new。显然调用错误的 operator delete 可能会产生毁灭性的结果。