Make getters work with immutable Data

[mlr-msft]

I'd like to be able to work with immutable data. e.g.:

impl<T> IpV4Header<T> {
    pub fn validate<T>(bytes: T) -> Result<()>
    where
        T: AsRef<[u8]>,
    { ...

Unfortunately, the accessor functions (e.g. get_protocol) that are generated require the AsMut<[u8]> trait. Is there something I'm not doing correctly?

Thanks in advance.

[dzamlo]

Ti use the getter and setter require that the type implement BitRange (and Bit for single bit field). And the implementation only exist for T: AsMut<[$slice_ty]> + AsRef<[$slice_ty] at the moment.

So yes, currently the getter will also require AsMut<[u8]>.

Maybe, I should split the BitRange trait in two (Only with a getter and one with a setter). And only require the necessary one of the two for each method.