Do not mark items as #[doc(hidden)] if they appear in your non-doc-hidden public API.
It's a terrible user experience.
I'm now browsing hyper's source code to understand what a trait bound actually means, since the trait itself is public but doc hidden
A lot of commits have been merged since the latest release - it's not enough to check the source, I even need to make sure I check the source at the right point in time!
Please, please, please - don't do this to your users.