[jackmott42]

In Rust you can usually use iterators to avoid bounds checks. This is idiomatic and the fast way to do things, so usually when using Rust you don't worry about this at all.

But, occasionally, you have some loop that can't be done with an iterator, AND its part of a tight loop where removing a single conditional jump matters to you. When that matters it is a real easy thing to use an unsafe block to index into the array without the check. The good news is then at least in your 1 million line program, the unsafe parts are only a few lines that you are responsible for being sure are correct.