std::bad_cast (3) Linux Manual Page

std::bad_cast – std::bad_cast

Synopsis

Defined in header <typeinfo>

class bad_cast : public std::exception;

An exception of this type is thrown when a dynamic_cast to a reference type fails the run-time check (e.g. because the types are not related by inheritance), and also from std::use_facet if the requested facet does not exist in the locale.
 std-bad cast-inheritance.svg
Inheritance diagram

Member functions

              constructs a new bad_cast object
constructor (public member function)

Inherited from std::exception

Member functions

destructor destroys the exception object
             (virtual public member function of std::exception)
[virtual]

what returns an explanatory string
             (virtual public member function of std::exception)
[virtual]

Example

// Run this code

#include <iostream>

#include <typeinfo>
struct Foo {
    virtual ~Foo()
    {
    }
};

struct Bar {
    virtual ~Bar()
    {
    }
};
int main()

{
    Bar b;
    try {
        Foo &f = dynamic_cast<Foo &>(b);
    } catch (const std::bad_cast &e) {
        std::cout << e.what() << '\n';
    }
}

Possible output:

  Bad dynamic cast