c++ - 在三级继承的情况下，dynamic_cast 会导致分段违规

Question

在三级继承的情况下似乎dynamic_cast不起作用。

print()应用程序在方法调用点（in 中）崩溃并出现分段错误（核心转储main()）。

这是代码：

#include <iostream>
#include <typeinfo>     //must be included to call any member functions for the typeinfo object returned by typeid()
using namespace std;
class CBase
{
public:
    virtual void print()
    {
        cout<<"CBase::print"<<endl;
    }
    virtual ~CBase()
    { }
};
class CDerivedA : public CBase
{
public:
    virtual void print()
    {
        cout<<"CDerivedA::print"<<endl;
    }
    virtual ~CDerivedA()
    {}
};
class CDerivedB : public CDerivedA
{
public:
    void print()
    {
        cout<<"CDerivedB::print"<<endl;
    }
};
int main()
{
    CBase* ptrB = new CDerivedA();
    CDerivedB* ptrDB = dynamic_cast<CDerivedB*>(ptrB);
    ptrDB->print();
    return 1;
}

Answer 1