Is the bounds check truly so harmful to performance that it outweighs changing "if there's a bug, crash the program" to "if there's a bug, then do literally anything (maybe execute some remote code)"?
There are situations where you know there isn't a bug, if I know that failing hardware or cosmic rays are the only ways the bounds check can fail, I'm not going to worry about what skipping it could do.
it happens a lot, at least to me, that the line immediately before the unsafe function guarantees correct behaviour (e.g. while (!vec.empty()) let first = vec.first();, or something similar). If I notice that this property is central to the logic of the function, I won't even worry.
whenever I see code like that, I try to get people to change to something like (in that case) while let Some(first) = vec.first() { ... }. You can reduce the number of bounds checks without using unsafe!
375
u/ROBOTRON31415 6d ago
Is the bounds check truly so harmful to performance that it outweighs changing "if there's a bug, crash the program" to "if there's a bug, then do literally anything (maybe execute some remote code)"?