That explains why so many docs for Rust packages are just a spew of types and traits.
From the user perspective I really dislike just being thrown a bunch of types with minimal to no actual docs. It seems more common with Cstyle headers to add docs.
If it looks like that, then I think those developers did not take a look using the cargo doc perspective. I definitely do that to add docs in the right places. And warn(missing_docs) is good to use too (warn on any public item).