Tracking Issue for "jump to definition"

[GuillaumeGomez]

Here what are the remaining things to be done:

• [ ] Improve "jump links" UI: for now it's highlighted background but it was suggested we could try an "underline dotted": https://github.com/rust-lang/rust/issues/88120
• [ ] Add support to go to both source definition and documentation page (if available!). We could do it by adding a popup when hovering the item. (#89157)
• [ ] Make all links go to source location, not documentation (currently, external types link to documentation)

Steps

To go through stabilization, we will gradually enable it in different places:

• [x] Enable it by default on the compiler docs (https://github.com/rust-lang/rust/pull/88292 and #89217)
• [ ] Enable it by default on the std docs
• [ ] Enable the feature by default (on nightly only) and remove the flag.
• [ ] Send the stabilization PR.

Implementation history

1. The initial PR which added the links to definition in the source code pages: https://github.com/rust-lang/rust/pull/84176
2. Add links for primitives in "jump to definition" feature: #88033
3. Add links for primitives: #91264

[jyn514]

Enable the feature by default (on nightly only) and reverse the flag (so that it disables instead of enabling).

I think we should not do this, this is exactly how we got in trouble with intra-doc links (see https://github.com/rust-lang/rust/issues/63305). Instead we should just enable it by default at the same time we remove the flag and stabilize the feature.

[GuillaumeGomez]

This is a very good point. I had in mind that maybe people would want to disable it but I guess we can always add it later on if the needs appear.