bump stdsimd; make intra_doc_link_resolution_failure an error again; make lints more consistent
I made `intra_doc_link_resolution_failure` warn so that it would properly respect `deny-warnings = false` in `config.toml`. `#[warn]` still become errors with `-D warnings` so I thought this was fine.
Turns out however that we don't pass `-D warnings` when running rustdoc, so for additional rustdoc-lints we need to set them to `deny`.
Also sue the opportunity to make the lint flags more consistent between libcore, liballoc, libstd.
Cc @gnzlbg for the *big* stdsimd update.
Remove strange formatting in `Ordering` docs.
I can't really fathom what the intent of the brackets is. The [original PR](#12956) doesn't give any hints. I think it seems fine without them.
Introduce RefCell::try_borrow_unguarded
*Come sit next to the fireplace with me, this is going to be a long story.*
So, you may already be aware that Servo has weird design constraints that forces us developers working on it to do weird things. The thing that interests us today is that we do layout on a separate thread with its own thread pool to do some things in parallel, whereas the data it uses comes from the script thread, which implements the entire DOM and related pieces, with `!Sync` data types such as `RefCell<T>`.
The invariant we maintain is that script does not do anything ever with the DOM data as long as layout is doing its job. That's all nice and all, but one thing we don't ensure is that we don't actually know if script was currently mutably borrowing some `RefCell<T>` prior to starting layout, which may lead to aliasing mutable memory and obviously undefined behaviour.
This PR reinstates `RefCell::borrow_state` so that [this method](https://github.com/servo/servo/blob/master/components/script/dom/bindings/cell.rs#L23-L30) can make use of it and return `None` if the cell was mutably borrowed.
Cc @SimonSapin
This commit changes the behavior of Formatter::debug_struct,
debug_tuple, debug_list, debug_set, and debug_map to render trailing
commas in {:#?} mode, which is the dominant style in modern Rust code.
Before:
Language {
name: "Rust",
trailing_commas: false
}
After:
Language {
name: "Rust",
trailing_commas: true,
}
Forward formatter settings to bounds of `Range<T>` in `fmt::Debug` impl
Before this change, formatter settings were lost when printing a `Range`. For example, printing a `Range<f32>` with `{:.2?}` would not apply the precision modifier when printing the floats. Now the `Debug` impls look a bit more verbose, but modifier are not lost.
---
I assume the exact output of `Debug` impls in `std` cannot be relied on by users and thus can change, right?
Updated the documentation of spin_loop and spin_loop_hint
# Description
- Updated the description of `core::hints::spin_loop`
- Updated the description of `core::async::spin_loop_hint`
Both documentation is rewritten to better reflect when one should prefer using a busy-wait spin-loop (and the `spin_loop` and `spin_loop_hint` functions) over `yield_now`. It also dives a little bit deeper on what the function actually does.
closes#55418
Be more direct about borrow contract
I always was confused by the difference between Borrow and AsRef, despite the fact that I've read all available docs at least a dozen of times.
I finally grokked the difference between the two when I realized the Borrow invariant:
> If you implement Borrow, you **must** make sure that Eq, Ord and Hash implementations are equivalent for borrowed and owned data
My problem was that this invariant is not stated explicitly in documentation, and instead some vague and philosophical notions are used.
So I suggest to mention the requirements of `Borrow` very explicitly: instead of "use Borrow when X and use AsRef when Y", let's phrase this as `Borrow` differs from `AsRef` in `W`, so that's why `Borrow` is for `X` and `AsRef` is for `Y`.
Note that this change could be seen as tightening contract of the Borrow. Let's say Alice has written the following code:
```rust
#[derive(PartialEq, Eq, Hash, PartialOrd, Ord)]
struct Person {
first_name: String,
last_name: String,
}
impl Borrow<str> for Person {
fn borrow(&self) -> &str { self.first_name.as_str() }
}
```
Now Bob uses this `Person` struct, puts it into `HashMap` and tries to look it up using `&str` for the first name. Bob's code naturally fails.
The question is, who is to blame: Alice, who has written the impl, or Bob, who uses the HashMap. If I read the current docs literally, I would say that `Bob` is to blame: `Eq` and `Hash` bounds appear on HashMap, so it is the HashMap which requires that they are consistent. By using a type for which the `Borrow` impl does not yield well-behaved `Eq`, Bob is violating contract of HashMap.
If, as this PR proposes, we unconditionally require that Eq & friends for borrow should be valid, then the blame shifts to Alice, which I think is more reasonable.
closes https://github.com/rust-lang/rust/issues/44868
Added documentation on the remainder (Rem) operator for floating points.
# Description
As has been explained in #57738 the remainder operator on floating points is not clear.
This PR requests adds some information on how the `Rem` / remainder operator on floating points works.
Note also that this description is for both `Rem<f32> for f32` and `Rem<f64> for f64` implementations.
Ps. I wasn't really sure on how to formulate things. So please suggest changes if you have better idea's!
closes#57738
Implement useful steps_between for all integers
We can use `usize::try_from` to convert steps from any size of integer.
This enables a meaningful `size_hint()` for larger ranges, rather than
always just `(0, None)`. Now they return the true `(len, Some(len))`
when it fits, otherwise `(usize::MAX, None)` for overflow.
Remove duplicated code from Iterator::{ne, lt, le, gt, ge}
This PR delegates `Iterator::ne` to `Iterator::eq` and `Iterator::{lt, le, gt, ge}` to `Iterator::partial_cmp`.
Oddly enough, this change actually simplifies the generated assembly [in some cases](https://rust.godbolt.org/z/riBtNe), although I don't understand assembly well enough to see if the longer assembly is doing something clever.
I also added two extremely simple benchmarks:
```
// before
test iter::bench_lt ... bench: 98,404 ns/iter (+/- 21,008)
test iter::bench_partial_cmp ... bench: 62,437 ns/iter (+/- 5,009)
// after
test iter::bench_lt ... bench: 61,757 ns/iter (+/- 8,770)
test iter::bench_partial_cmp ... bench: 62,151 ns/iter (+/- 13,753)
```
I have no idea why the current `lt`/`le`/`gt`/`ge` implementations don't seem to be compiled optimally, but simply having them call `partial_cmp` seems to be an improvement.
See #44729 for a previous discussion.
Before this change, formatter settings were lost when printing a
`Range`. For example, printing a `Range<f32>` with `{:.2?}` would not
apply the precision modifier when printing the floats. Now the `Debug`
impls look a bit more verbose, but modifier are not lost.
Stabilize refcell_replace_swap feature
Please be kind, this is my first time contributing. 😄
I noticed #43570 only needs stabilizing (and I need it for a side project I'm working on), so I followed the [guide](https://rust-lang.github.io/rustc-guide/stabilization_guide.html#stabilization-pr) to move things forward.
I'm happy to amend things if needed, let me know!
