Load data using the correct byte order.

[emberian]

Except for the type named HeaderPt1, the rest of the ELF data uses the byte order indicated by the e_ident. Currently data will be read using the host's native byte order, which isn't correct in general.

It's not clear to me how to fix this, as the parsing approach taken by zero isn't particularly friendly to reinterpreting data.

[emberian]

One option is to add a phantom type indicating the byte order of the data, and wrapping all multibyte values with a ByteOrder<E, T>, where T is the primitive numeric type being wrapped and E is the byte order direction. This E phantom type would need to be threaded throughout all of the everything. Parsing an ELF structure would then be some form of:

fn parse_header<E: ByteOrder>(input: &[u8]) -> Option<Header<'a, E>>  {
    let ident = parse_ident(input);
    if E::same_byteorder(ident.data) {
        Some(f(parse_header(input)))
    } else {
        None
    }
}

Most code can be generic over the byteorder marker completely, but it's correctness-critical that constructing the wrapper type enforces the correct byteorder.