Some basic OO questions over the phone by a recruiter, then get invited to the site for another 3hour interview with 3 engineers (1hour each) on C++, OO design question and standard algorithm, IQ, EQ questions.
Nothing especially hard on C++, if you have good hand on experience, but do read up a bit to revise what you have learnt. Do expect to write code on the spot, but not to worry so much if you do have programming experience, these questions are just to understand your actual coding skills, and not trying to pushing hard on you.
Do get mentally prepared to come out with OO solution for geometry related question, again, nothing is especially hard here, use your common sense and a bit of OO experience, you can get pass this with some helps from the interviewer. I think the key is not to get the perfect solution in the shortest amount of time, the key here is to voice out your thought, interact with the interviewer, and making progress in the discussion, to show how you think is more important than the solution itself, but of course, if you can come out with some solution with clear thought process, that would be the best.
Lastly, standard algorithm, IQ, EQ questions will be asked. Just be relax and try your best.
To summarise, it would be good if you can answer all questions but in the end, it also depend on luck (other factors you can't control: e.g. (1) number of hired position vs number of interview candidate x how strong is your competitors, if the ratio is high, meaning your chance to get hired is higher. (2) whether you know the answer to the questions being asked, sometimes it is just by luck, because nobody is super human that can know everything (3) your interviewers interpretation of your strength also matter)