[eqvinox]

The "isn't C" argument is more about the library as a whole, not specifically about the fat pointer suggestions. (Please look at the github repo, IMHO it's obvious.)

Placing a length "before" a pointer is perfectly fine on a _technical_ level. It's also how glibc's malloc works, it has its own data before any allocation it returns. However, hackiness is not the question here - it's whether it's the "best" approach. I simply believe, based on my own experiences, that twin pointers cover/win out in a much larger subset of applicable scenarios.

As for how to implement it - declare a struct with 2 pointers in it. Or just pass 2 pointers around.