bad_cast

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首先学习一下bad_cast

在微软的解释:The bad_cast exception is thrown by thedynamic_cast operator as the result of a failed cast to a reference type.

catch (bad_cast)   statement

bad_cast 的接口是:

class bad_cast : public exception {public:   bad_cast(const char * _Message = "bad cast");   bad_cast(const bad_cast &);   virtual ~bad_cast();};

最新的VS2012的代码是：

class _CRTIMP_PURE bad_cast : public exception {public:#ifdef _M_CEE_PURE    __CLR_OR_THIS_CALL bad_cast(const char * _Message = "bad cast")        : exception(_Message)    {}    __CLR_OR_THIS_CALL bad_cast(const bad_cast &_That)        : exception(_That)    {}    virtual __CLR_OR_THIS_CALL ~bad_cast() _NOEXCEPT    {}#else   /* _M_CEE_PURE */    __CLR_OR_THIS_CALL bad_cast(const char * _Message = "bad cast");    __CLR_OR_THIS_CALL bad_cast(const bad_cast &);    virtual __CLR_OR_THIS_CALL ~bad_cast() _NOEXCEPT;#endif  /* _M_CEE_PURE */};

// expre_bad_cast_Exception.cpp// compile with: /EHsc /GR#include <typeinfo.h>#include <iostream>class Shape {public:   virtual void virtualfunc() const {}};class Circle: public Shape {public:   virtual void virtualfunc() const {}};using namespace std;int main() {   Shape shape_instance;   Shape& ref_shape = shape_instance;   try {      Circle& ref_circle = dynamic_cast<Circle&>(ref_shape);    }   catch (bad_cast b) {      cout << "Caught: " << b.what();   }}