rustdoc has the ability to embed usage examples in the doc comments, and automatically test them. also module-level documentation is doable via doc comments in the module main file. rust doesn't force you to write good documentation, but the tools are all there and I often see great documentation for rust crates that was generated with cargo doc. For example the Rocket docs are full of code examples on both the module and function level: https://api.rocket.rs
I think there's something to be said for javadoc, cargo doc, etc encouraging documentation to hew closely to the structure of the code as opposed to a free-form documentation system that can include multiple pages about tasks, getting started, etc. But the vast majority of projects don't bother to set that up, and the javadoc approach makes it very low friction to add docs to existing code that probably already has comments explaining how to use it.
That’s the barebones minimum, because in those contexts the examples are going to be relatively trivial. Often I find them to be no more helpful than the signature doc itself.
Even trivial examples that actually compile are better than none. because rust uses real code and markdown reading code and docs is the same thing in many cases, no need to even render to html, absolutely minimal markup noise.
I love rust docs. Speaking from many years of using mostly poorly maintained javadocs and well maintained man pages.
I think there's something to be said for javadoc, cargo doc, etc encouraging documentation to hew closely to the structure of the code as opposed to a free-form documentation system that can include multiple pages about tasks, getting started, etc. But the vast majority of projects don't bother to set that up, and the javadoc approach makes it very low friction to add docs to existing code that probably already has comments explaining how to use it.