I think the most dangerous part of C is that many people assume C is perfectly efficient. It's as if C was the "100%" of performance and other languages are converging towards it as they get better.

But I don't see how this is true. Pointer aliasing is the biggest example probably:

http://www.futurechips.org/tips-for-power-coders/how-to-tric...

And then there is the huge abstraction penalty for things like `qsort()` where C++ is actually way ahead of C.