| description | Learn more about: bad_typeid exception | ||
|---|---|---|---|
| title | bad_typeid exception | ||
| ms.date | 10/04/2019 | ||
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| ms.assetid | 5963ed58-4ede-4597-957d-f7bbd06299c2 |
The bad_typeid exception is thrown by the typeid operator when the operand for typeid is a NULL pointer.
catch (bad_typeid)
statement
The interface for bad_typeid is:
class bad_typeid : public exception
{
public:
bad_typeid();
bad_typeid(const char * _Message = "bad typeid");
bad_typeid(const bad_typeid &);
virtual ~bad_typeid();
bad_typeid& operator=(const bad_typeid&);
const char* what() const;
};The following example shows the typeid operator throwing a bad_typeid exception.
// expre_bad_typeid.cpp
// compile with: /EHsc /GR
#include <typeinfo>
#include <iostream>
class A{
public:
// object for class needs vtable
// for RTTI
virtual ~A();
};
using namespace std;
int main() {
A* a = NULL;
try {
cout << typeid(*a).name() << endl; // Error condition
}
catch (bad_typeid){
cout << "Object is NULL" << endl;
}
}Object is NULL