This is 682889fb06, but for arrays instead.
For non-generics, this retains links to the array page, but instead of
trying to link it all, it only links the length part, which distinguishes
arrays from slices.
For generics, the entire thing becomes a link, just like slices.
* Reduce duplicate impls; show only the `fn (T)` and include a sentence
saying that there exists up to twelve of them.
* Show `Copy` and `Clone`.
* Show auto traits like `Send` and `Sync`, and blanket impls like `Any`.
Remove most box syntax from librustdoc
This is the second attempt after the librustdoc specific changes have been reverted from #87781 in #89134, due to a minor, but exant regression caused by the changes. ~~There have been some changes to librustdoc in the past and maybe thanks to them there is no regression any more. If there is still a regression, one can investigate further and maybe find ways to fix the regressions. Thus, i request a perf run.~~ Edit: turns out there is still a regression, but it's caused only by a subset of the changes. So I've changed this PR to only contains the changes that don't cause any performance regressions, keeping the regression causing changes for a later PR.
This is 682889fb06 but for tuples. The
reasoning is the same:
* This commit also changes it so that tuples with all-generic elements still
link to the primitive.tuple.html page, just like slices. So there still
plenty of on-ramps for anybody who doesn't know about it.
* It's too hard to see when round braces are a separate link from the type
inside of them.
* It's too hard to click even if you do notice them.
Since #97668 was merged, the slice::get function now looks like this:

That whole thing, `[T]`, is a single link to `primitive.slice.html`. This
definitely fixes it for this case, but it's not obvious what we should do for
slices of concrete types:

There are actually three links in that `[u8]`: the opening brace `[` is a
link to `primitive.slice.html`, the `u8` is a link to `primitive.u8.html`,
and the final `]` is a link to `primitive.slice.html`. This is a serious
[usability bug](https://usability.yale.edu/web-accessibility/articles/links):
the square braces are much too small for anyone who doesn't have perfect
motor control using mouse or touch, provide an excessive number of tab stops
for anyone using keyboard, and no visual indication whatsoever that they're
separate links.
Now that slices of generic types are linked, it seems reasonable to err on
the side of less clutter and stop linking concrete slices to the slice page.
This commit adds a new unstable attribute, `#[doc(tuple_varadic)]`, that
shows a 1-tuple as `(T, ...)` instead of just `(T,)`, and links to a section
in the tuple primitive docs that talks about these.
rustdoc: Reduce clean::Type size
There is no need to keep the `DefId` around since it's allow used to compute if we should show a cast or not. As such, we can simply directly store the boolean.
I think it's not what you had in mind `@camelid` but I guess it's still an improvement? 😉
It was discussed in https://github.com/rust-lang/rust/pull/93941.
r? `@camelid`
Only crate root def-ids don't have a parent, and in majority of cases the argument of `DefIdTree::parent` cannot be a crate root.
So we now panic by default in `parent` and introduce a new non-panicing function `opt_parent` for cases where the argument can be a crate root.
Same applies to `local_parent`/`opt_local_parent`.