One flip side of this is when undefined behavior in one library invalidates critical assumptions underlying the correctness of another, and tracking it down is

One flip side of this is when undefined behavior in one library invalidates critical assumptions underlying the correctness of another, and tracking it down is a nightmare. I’d much rather, in general, get predictable and understandable semantics and have to struggle for performance than get predictable and understandable performance and struggle for semantics. Even more so, I’d rather use software that faced that profile of challenges. You can see when the program is slow at runtime, but you often can’t see when it’s wrong at runtime.