One thing I remember vividly was an off-by-one error off a colleague in a nested loop. Since we were using periodic boundary conditions, the result looked almos

One thing I remember vividly was an off-by-one error off a colleague in a nested loop. Since we were using periodic boundary conditions, the result looked almost right, but of course the very last read would be garbage. Depending on the lattice size this was not a glaring problem, but sometimes the very last (out-of-bounds) read would trigger a segfault. Incidentally, I rewrote that piece of code using a self-made `lattice_iterator` in C++ that "linearised" the code just to simplify it and make debugging easier and everything started to work. We found the off-by-one error afterwards by comparing the iteration behaviour of a single run. This kind of problem can be caught by tests (though it's difficult, you can't tell me that you are really testing each individual iteration behaviour of your code), the advantage of Rust's approach is that this wouldn't even have passed the compiler.