Error: Cannot use typeid with -fno-rtti

Question

I´m getting this "Cannot use typeid with -fno-rtti" when I´m trying to compile my project, I´m using an opencv framework. I googled the problem but, it seems the errors I found in internet does not have relation with my problem. I don´t know if the problem is related with the includes, the code or the compiler.

Xcode is giving me the error a lot of times, but the first error is here:

virtual const std::type_info& type() { return typeid(T); }

Answer 1

RTTI stands for Run Time Type Information, and typeid is an RTTI-feature. So turning off RTTI (-fno-rtti) also disables features like typeid.

See http://en.wikipedia.org/wiki/RTTI for more information about RTTI in C++.

Answer 2

It's telling you the error right in the message: if you use the no-rtti flag on the compiler, then typeid is not going to be available. Just enable RTTI; it's part of C++ after all.