Comment by nostrademons

Sure, but for something like that whatever constructs the view can use an opaque index type like Animats suggested, which under the hood is probably a byte index. The slice itself is kinda the opaque index, and then it can just have privileged access to some kind of unsafe_byteIndex accessor.

There are a variety of reasons why unsafe byte indexing is needed anyway (zero-copy?), it just shouldn’t be the default tool that application programmers reach for.