Here are some things I would ask about if someone claimed to be capable of answering C++ questions and was applying for a senior level position.
Explain placement new and when you would use it
What are templates
What is template specialization
Why should you make the destructor of a base class virtual
What is RAII
This list could become exhausted but if I was interviewing I would skip over the basic questions like constructor vs. destructor or anything that was abstractly related to Object Oriented development.
If you do not know C++, especially modern C++ you have to be upfront about this. Don't try to fake your way as the interviewer would know immediately. What I find most frustrating when interviewing candidates are ones that try to claim they can develop C++ but really only know C.
This of course is not an exhaustive list of questions that could be asked during an interview. The most important ones are regarding critical thinking, designing under pressure and confidence in solutions that are presented.