How to avoid bounds checking?

[bluss]

@LilianMoraru

fn with_bounds(some_slice: &[usize]) {
    let len = some_slice.len();

    for it in 0..len {
        // calling some_slice[it] checks for bounds
    }
}

I would expect the optimizer to elide all bounds checks in this particular example. This a trivial case: The loop condition is it < len. The bounds check condition is it < len, too, and so it can be optimized out. You can verify this by inspecting the optimized (release mode) code.

Still, in this situation, prefer iterators. Using for element in some_slice { is very easy. Use for (index, element) in some_slice.iter().enumerate() { if you need the index too.