Perhaps that should be a hint that you are asking the wrong questions. The job of a software developer is to solve customer problems. Not being C++ language exp

Perhaps that should be a hint that you are asking the wrong questions. The job of a software developer is to solve customer problems. Not being C++ language experts. So instead ask how they have solved real customer problems, what the tech trade-offs were, why they chose the solutions they ended up with, what other possible solutions they could have used, the hardest bugs they have fixed, how they fixed it etc. I have 30+ years of experience, and have hired many C++ developers, while working for different companies around the world. And my success rate in hiring good developers have been very high. Using exactly the questions I mentioned above.