Can not use dynamic_cast to a const object

Question

I want to write a method where a `Base` object pointer will be passed as a parameter, and inside the method it will be casted to derived object pointer. ``` void func( const Base* const obj){ Derived* der = dynamic_cast(obj); } ``` But it shows error because dynamic cast cannot cast away const specifier. But I am not understanding why `const` specifier has to be removed here, all I am doing is creating a derived pointer which should point to some offset amount after the base pointer. I also tried `const Derived* const der = dynamic_cast(obj);`, but no result. It is important to pass the parameter as `const`. How can I do this? Do I have to do it in the ugly way of first applying `const_cast` then `dynamic_cast`? is there any better way?

Accepted Answer

You're casting away `const` because you didn't do this: ``` const Derived* der = dynamic_cast(obj); ``` If you actually need a `Derived*` then you need to ``` Derived* der = dynamic_cast(const_cast(obj)); ```

Can not use dynamic_cast to a const object

Solution

Problem