Rust non zero integers

I recently discovered Rust's NonZero types which are implemented for all ints and uints, and as the name implies are integers which are guaranteed to not be null. This may seem a bit silly, but this one guarantee is what enables size_of::Option<NonZero<u8>>() == size_of::NonZero<u8>(), which basically means that an Option of a NonZero integer has no additional cost compared to an integer. This is useful whenever 0 is used as a sentinel value, since it brings that information into the type system and increases robustness, given that now 0 is not a sentinel value with the same underlying type, but a different type altogether.