What are some “interview questions” I could ask that would let me know if candidates really know their stuff?

This answer is primarily for non-technical managers and HR folks who are trying to do a good job at interviewing C++ candidates. If you’re a C++ programmer about to be interviewed, and if you’re lurking in this FAQ hoping to know the questions they’ll ask you ahead of time so you can avoid having to really learn C++, shame on you: spend your time becoming technically competent and you won’t have to try to “cheat” your way through life!

Back to the non-technical manager / HR person: obviously you are eminently qualified to judge whether a candidate is a good “fit” with your company’s culture. However there are enough charlatans, wannabes, and posers out there that you really need to team up with someone who is technically competent in order to make sure the candidate has the right level of technical skill. A lot of companies have been burned by hiring nice but incompetent duds — people who were incompetent in spite of the fact that they knew the answers to a few obscure questions. The only way to smoke out the posers and wannabes is to get someone in with you who can ask penetrating technical questions. You have no hope whatsoever of doing that yourself. Even if I gave you a bunch of “tricky questions,” they wouldn’t smoke out the bad guys.

Your technical sidekick might not be (and often isn’t) qualified to judge the candidate on personality or soft skills, so please don’t abdicate your role as the final arbiter in the decision making process. But please don’t think you can ask a half dozen C++ questions and have the slightest clue if the candidate really knows what they’re talking about from a technical perspective.

Having said all that, if you’re technical enough to read the C++ FAQ, you can dig up a lot of good interview questions here. The FAQ has a lot of goodies that will separate the wheat from the chaff. The FAQ focuses on what programmers should do, as opposed to merely what the compiler will let them do. There are things that can be done in C++ but shouldn’t be done. The FAQ helps people separate those two.