Make `Atomic*::from_mut` return `&mut Atomic*`
```rust
impl Atomic* {
pub fn from_mut(v: &mut bool) -> &mut Self;
// ^^^^---- previously was just a &
}
```
This PR makes `from_mut` atomic methods tracked in #76314 return unique references to atomic types, instead of shared ones. This makes `from_mut` and `get_mut` inverses of each other, allowing to undo either of them by the other.
r? `@RalfJung`
(as Ralf was [concerned](https://github.com/rust-lang/rust/issues/76314#issuecomment-955062593) about this)
Implemented const casts of raw pointers
This adds `as_mut()` method for `*const T` and `as_const()` for `*mut T`
which are intended to make casting of consts safer. This was discussed
in the [internals discussion][discussion].
Given that this is a simple change and multiple people agreed to it including `@RalfJung` I decided to go ahead and open the PR.
[discussion]: https://internals.rust-lang.org/t/casting-constness-can-be-risky-heres-a-simple-fix/15933
Add some missing `#[must_use]` to some `f{32,64}` operations
This PR adds `#[must_use]` to the following methods:
- `f32::recip`
- `f32::max`
- `f32::min`
- `f32::maximum`
- `f32::minimum`
and their equivalents in `f64`.
These methods all produce a new value without modifying the original and so are pointless to call without using the result.
Add note about non_exhaustive to variant_count
Since `variant_count` isn't returning something opaque, I thought it makes sense to explicitly call out that its return value may change for some enums.
cc #73662
Previously suggested in https://github.com/rust-lang/rfcs/issues/2854.
It makes sense to have this since `char` implements `From<u8>`. Likewise
`u32`, `u64`, and `u128` (since #79502) implement `From<char>`.
Rollup of 7 pull requests
Successful merges:
- #92092 (Drop guards in slice sorting derive src pointers from &mut T, which is invalidated by interior mutation in comparison)
- #92388 (Fix a minor mistake in `String::try_reserve_exact` examples)
- #92442 (Add negative `impl` for `Ord`, `PartialOrd` on `LocalDefId`)
- #92483 (Stabilize `result_cloned` and `result_copied`)
- #92574 (Add RISC-V detection macro and more architecture instructions)
- #92575 (ast: Always keep a `NodeId` in `ast::Crate`)
- #92583 (⬆️ rust-analyzer)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add RISC-V detection macro and more architecture instructions
This pull request includes:
- Update `stdarch` dependency to include ratified RISC-V supervisor and hypervisor instruction intrinsics which is useful in Rust kernel development
- Add macro `is_riscv_feature_detected!`
- Modify impl of `core::hint::spin_loop` to comply with latest version of `core::arch`
After this update, users may now develop RISC-V kernels and user applications more freely.
r? `@Amanieu`
Drop guards in slice sorting derive src pointers from &mut T, which is invalidated by interior mutation in comparison
I tried to run https://github.com/rust-lang/miri-test-libstd on `alloc` with `-Zmiri-track-raw-pointers`, and got a failure on the test `slice::panic_safe`. The test failure has nothing to do with panic safety, it's from how the test tests for panic safety.
I minimized the test failure into this very silly program:
```rust
use std::cell::Cell;
use std::cmp::Ordering;
#[derive(Clone)]
struct Evil(Cell<usize>);
fn main() {
let mut input = vec![Evil(Cell::new(0)); 3];
// Hits the bug pattern via CopyOnDrop in core
input.sort_unstable_by(|a, _b| {
a.0.set(0);
Ordering::Less
});
// Hits the bug pattern via InsertionHole in alloc
input.sort_by(|_a, b| {
b.0.set(0);
Ordering::Less
});
}
```
To fix this, I'm just removing the mutability/uniqueness where it wasn't required.
Rollup of 7 pull requests
Successful merges:
- #91587 (core::ops::unsize: improve docs for DispatchFromDyn)
- #91907 (Allow `_` as the length of array types and repeat expressions)
- #92515 (RustWrapper: adapt for an LLVM API change)
- #92516 (Do not use deprecated -Zsymbol-mangling-version in bootstrap)
- #92530 (Move `contains` method of Option and Result lower in docs)
- #92546 (Update books)
- #92551 (rename StackPopClean::None to Root)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Move `contains` method of Option and Result lower in docs
Follow-up to #92444 trying to get the `Option` and `Result` rustdocs in better shape.
This addresses the request in https://github.com/rust-lang/rust/issues/62358#issuecomment-645676285. The `contains` methods are previously too high up in the docs on both `Option` and `Result` — stuff like `ok` and `map` and `and_then` should all be featured higher than `contains`. All of those are more ubiquitously useful than `contains`.
- Do not `#[doc(hidden)]` the `#[derive]` macro attribute
- Add a link to the reference section to `derive`'s inherent docs
- Do the same for `#[test]` and `#[global_allocator]`
- Fix `GlobalAlloc` link (why is it on `core` and not `alloc`?)
- Try `no_inline`-ing the `std` reexports from `core`
- Revert "Try `no_inline`-ing the `std` reexports from `core`"
- Address PR review
- Also document the unstable macros
Consolidate Result's and Option's methods into fewer impl blocks
`Result`'s and `Option`'s methods have historically been separated up into `impl` blocks based on their trait bounds, with the bounds specified on type parameters of the impl block. I find this unhelpful because closely related methods, like `unwrap_or` and `unwrap_or_default`, end up disproportionately far apart in source code and rustdocs:
<pre>
impl<T> Option<T> {
pub fn unwrap_or(self, default: T) -> T {
...
}
<img alt="one eternity later" src="https://user-images.githubusercontent.com/1940490/147780325-ad4e01a4-c971-436e-bdf4-e755f2d35f15.jpg" width="750">
}
impl<T: Default> Option<T> {
pub fn unwrap_or_default(self) -> T {
...
}
}
</pre>
I'd prefer for method to be in as few impl blocks as possible, with the most logical grouping within each impl block. Any bounds needed can be written as `where` clauses on the method instead:
```rust
impl<T> Option<T> {
pub fn unwrap_or(self, default: T) -> T {
...
}
pub fn unwrap_or_default(self) -> T
where
T: Default,
{
...
}
}
```
*Warning: the end-to-end diff of this PR is computed confusingly by git / rendered confusingly by GitHub; it's practically impossible to review that way. I've broken the PR into commits that move small groups of methods for which git behaves better — these each should be easily individually reviewable.*
Track caller of slice split and swap
Improves error location for `slice.split_at*()` and `slice.swap()`.
These are generic inline functions, so the `#[track_caller]` on them is free — only changes a value of an argument already passed to panicking code.
Add `#[inline]` modifier to `TypeId::of`
It was already inlined but it happened only in 4th InlinerPass on my testcase.
With `#[inline]` modifier it happens on 2nd pass.
Closes#74362
disable test with self-referential generator on Miri
Running the libcore test suite in Miri currently fails due to the known incompatibility of self-referential generators with Miri's aliasing checks (https://github.com/rust-lang/unsafe-code-guidelines/issues/148). So let's disable that test in Miri for now.
