I agree with you that one language will take the productivity you've gained in a later stage, but we would need to subtract the time fixing those bugs, as compa

I agree with you that one language will take the productivity you've gained in a later stage, but we would need to subtract the time fixing those bugs, as compared to the time spent on code to avoid them in both languages (one before and another later). I'm pretty sure that a lot of people will be more productive with Rust as compared with C++ as with others will be the opposite. So i guess in by making an average over those two crowds, i doubt they will differ that much. The sort of bugs Rust will avoid that are kind of hard to debug, giving it doesn't happen that often is the problem of shared state in a multi-thread environment.. the other kinds are often easy to spot in C++, the only difference is that they are caught in runtime.