In my case, I needed to know whether or not a member exists in order to implement object tracking. I basically have a macro that inserts a member into a class, and calls that member's constructor with the "this" pointer of the tracked class. A different function needs to know, at compile time, whether or not a class is tracked, as the way memory is allocated differs.

I didn't want to use inheritance, as tracking is disabled in a shipped build, and I want it to have as little effect on the codebase as possible. So, the simplest option seemed to be to check whether or not the member exists (and assume the name is unique enough an untracked object will not contain it). This was good enough for my purposes.

I'm not as familiar with C#, but attributes seems like a potential alternative, though I'm not sure they can be fully removed from a release build. And, of course, C# is garbage collected, which is not ideal for all types of software. If there is a better alternative, I'd be interested in hearing it though!

Don't get me wrong, I'd absolutely love a "better" C++. Rust is a great language, but I personally don't feel that the safety guarantees are worth it for every class of software. If a video game crashes, the world isn't going to end.