Generate docs for multiple targets

I was exploring tokio's source code and noticed that all methods gated to windows do not show up in the docs. This probably happens because the docs are generated in a non-windows machine.
Then I tried something like cargo doc --all-targets --open and that doesn't work.

How does std do it? Their docs expose every method, gated or not. An example from std that I'm trying to decifer

An example would be process docs vs its source.

We have an issue about this: Make windows-only APIs show up on docs.rs · Issue #3275 · tokio-rs/tokio · GitHub

You can already view them if you pick the windows target in the top of the docs.rs page.

Thank you for the link. I searched for something like that but was querying for "all-targets", and thus couldn't find it.
I guess this would be a feature request on cargo doc... Having docs show as they do in std would be nicer but oh well ¯\_(ツ)_/¯.
I didn't realise that dropdown was meant for switching the docs. I always thought of it as the "tested"/"supported" platforms, TIL.