Question: Are there any aspects to the C++ programming language where the code is known to be slower than the equivalent C language? Obviously this would be excluding the OO features like virtual functions and vtable features etc.

I am wondering whether, when you are programming in a latency-critical area (and you aren't worried about OO features) whether you could stick with basic C++ or would C be better?

Answer: 
Contrary to what many C programmers like to think, one can often write tighter and faster code in C++ all without having to sacrifice a great deal in design.

I can't think of anything in C++ that is slower than its counterpart in C. Virtual functions NOT excluded.
Does *Latency critical* mean *as fast as possible* or does it simply mean that *everything has to run in predictable time*? 

If it is the second case, then the only things that don't run in predictable time are `new`, `delete` and `try/catch`. In embedded programming there are directives to avoid such calls. In other cases, especially in C++11 you might notice some things are faster (std::sort is faster than C's sort() ) and some are marginally slower. 

But what you gain over C++ is higher abstraction levels and you don't get the C-style bugs (like the typical `malloc()` without a corresponding `free()` )