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title: "bad_cast Exception | Microsoft Docs"
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---
# bad_cast Exception
The `bad_cast` exception is thrown by the `dynamic_cast` operator as the result of a failed cast to a reference type.  
  
## Syntax  
  
```  
catch (bad_cast)  
   statement  
```  
  
## Remarks  
 The interface for `bad_cast` is:  
  
```  
class bad_cast : public exception {  
public:  
   bad_cast(const char * _Message = "bad cast");  
   bad_cast(const bad_cast &);  
   virtual ~bad_cast();  
};  
```  
  
 The following code contains an example of a failed `dynamic_cast` that throws the `bad_cast` exception.  
  
```  
// 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();  
   }  
}  
```  
  
 The exception is thrown because the object being cast (a Shape) is not derived from the specified cast type (Circle). To avoid the exception, add these declarations to `main`:  
  
```  
Circle circle_instance;  
Circle& ref_circle = circle_instance;  
```  
  
 Then reverse the sense of the cast in the `try` block as follows:  
  
```  
Shape& ref_shape = dynamic_cast<Shape&>(ref_circle);  
```  
  
## See Also  
 [dynamic_cast Operator](../cpp/dynamic-cast-operator.md)   
 [Keywords](../cpp/keywords-cpp.md)   
 [C++ Exception Handling](../cpp/cpp-exception-handling.md)