There is a problem here - it's verbose and prone to silent-ish breakage if the surrounding context changes e.g. due to refactors (well, probably not with this tiny example, but I hope you know what I mean). Thankfully, there is also a solution to this problem: https://github.com/rust-lang/rust/issues/90091

split_array will eventually allow something like the following, which avoids any explicit indexing and will fail to compile if the sizes don't match up:

    struct IVec2(i32, i32);

    impl IVec2 {
        fn parse(b: [u8; 8]) -> Self {
            let (first, second) = b.split_array();
            IVec2(i32::from_le_bytes(first),
                  i32::from_le_bytes(second))
        }
    }