[the8472]

> eg. fn(n: usize, arr1: &[i32; n], arr2: &[i32, n]) allowed the function body to assume the two slices can be zipped without losing elements.

Often you can wrangle the optimizer into eliminating all but one bounds check by passing slices instead and then slicing one of the inputs in terms of length of the other. The Zip iterator adapter also has optimizations for the case of two slices where iteration will only require two length queries at the beginning and no further bounds checks.