c++castingrtti

How do I typecast with type_info?

I've stored a pointer to a type_info object.

int MyVariable = 123;
const std::type_info* Datatype = &typeid(MyVariable);

How might I use this to typecast another variable to that type? I tried this, but it doesn't work:

std::cout << ((*Datatype)3.14) << std::endl;

Using the function form of typecasting doesn't work, either:

std::cout << (*Datatype(3.14)) << std::endl;
Solution

  • I don't think such casting can be done. Suppose you could do "dynamic" casting like this at runtime (not to mean dynamic_cast). Then if you used the result of the cast to call a function the compiler could no longer do type checking on the parameters and you could invoke a function call that doesn't actually exist.

    Therefore it's not possible for this to work.