Commit Graph

1926 Commits

Author SHA1 Message Date
Scott McMurray
6648134434 Apply review feedback; Fix no_global_oom_handling build 2022-12-08 22:08:55 -08:00
Scott McMurray
58e60ac211 Make VecDeque::from_iter O(1) from vec(_deque)::IntoIter 2022-12-08 01:42:45 -08:00
bors
203c8765ea Auto merge of - scottmcm:vecdeque-vs-vec, r=Mark-Simulacrum
Send `VecDeque::from_iter` via `Vec::from_iter`

Since it's O(1) to convert between them now, might as well reuse the logic.

Mostly for the various specializations it does, but might also save some monomorphization work if, say, people collect slice iterators into both `Vec`s and `VecDeque`s.
2022-12-05 08:45:03 +00:00
Yuki Okushi
9f3ccd4bf6
Rollup merge of - HintringerFabian:improve_docs, r=JohnTitor
improve doc of into_boxed_slice and impl From<Vec<T>> for Box<[T]>

Improves description of `into_boxed_slice`, and adds example to `impl From<Vec<T>> for Box<[T]>`.
Fixes 
2022-12-03 12:51:27 +09:00
Markus Everling
c959fbe771 Fix typo in comment 2022-12-01 12:44:29 +01:00
Markus Everling
929003aacf Make VecDeque::new_in unstably const 2022-12-01 12:15:29 +01:00
Scott McMurray
a964a37211 Send VecDeque::from_iter via Vec::from_iter
Since it's O(1) to convert between them now, might as well reuse the logic.

Mostly for the various specializations it does, but might also save some monomorphization work if, say, people collect slice iterators into both `Vec`s and `VecDeque`s.
2022-11-29 00:24:15 -08:00
Fabian Hintringer
f9490c8121 improve doc 2022-11-28 22:42:05 +01:00
bors
69df0f2c2f Auto merge of - Sp00ph:master, r=scottmcm
Update VecDeque implementation to use head+len instead of head+tail

(See )

This changes `alloc::collections::VecDeque`'s internal representation from using head and tail indices to using a head index and a length field. It has a few advantages over the current design:
* It allows the buffer to be of length 0, which means the `VecDeque::new` new longer has to allocate and could be changed to a `const fn`
* It allows the `VecDeque` to fill the buffer completely, unlike the old implementation, which always had to leave a free space
* It removes the restriction for the size to be a power of two, allowing it to properly `shrink_to_fit`, unlike the old `VecDeque`
* The above points also combine to allow the `Vec<T> -> VecDeque<T>` conversion to be very cheap and guaranteed O(1). I mention this in the `From<Vec<T>>` impl, but it's not a strong guarantee just yet, as that would likely need some form of API change proposal.

All the tests seem to pass for the new `VecDeque`, with some slight adjustments.

r? `@scottmcm`
2022-11-28 10:39:47 +00:00
bors
faf1891deb Auto merge of - scottmcm:refactor-extend-func, r=the8472
Stop peeling the last iteration of the loop in `Vec::resize_with`

`resize_with` uses the `ExtendWith` code that peels the last iteration:
341d8b8a2c/library/alloc/src/vec/mod.rs (L2525-L2529)

But that's kinda weird for `ExtendFunc` because it does the same thing on the last iteration anyway:
341d8b8a2c/library/alloc/src/vec/mod.rs (L2494-L2502)

So this just has it use the normal `extend`-from-`TrustedLen` code instead.

r? `@ghost`
2022-11-27 00:58:50 +00:00
Markus Everling
acf95adfe2 Add second test case in make_contiguous_head_to_end 2022-11-26 23:08:57 +01:00
Markus Everling
451259811a Improve slow path in make_contiguous 2022-11-26 22:55:39 +01:00
Markus Everling
f6f25983c6 Don't use Take in SpecExtend impl 2022-11-26 00:44:24 +01:00
Scott McMurray
9d68a1a74c Tune RepeatWith::try_fold and Take::for_each and Vec::extend_trusted 2022-11-24 19:14:19 -08:00
Markus Everling
ecca8c5328 Changes according to code review 2022-11-25 03:39:59 +01:00
Scott McMurray
a8954f1f6a Stop peeling the last iteration of the loop in Vec::repeat_with 2022-11-24 03:12:54 -08:00
Scott McMurray
1c966e7f15 Extract the logic for TrustedLen to a named method that can be called directly 2022-11-24 03:12:05 -08:00
Thom Chiovoloni
54a6d4edbc
Add #![deny(unsafe_op_in_unsafe_fn)] in liballoc tests 2022-11-23 08:10:17 -08:00
Manish Goregaokar
316bda89e4
Rollup merge of - RalfJung:alloc-strict-provenance, r=thomcc
enable fuzzy_provenance_casts lint in liballoc and libstd

r? ````@thomcc````
2022-11-22 22:54:41 -05:00
The 8472
d576a9b241 add test for issue 104726 2022-11-22 20:58:43 +01:00
Manish Goregaokar
2f8dbe3797
Rollup merge of - dns2utf8:box_docs, r=dtolnay
Make the Box one-liner more descriptive

I would like to avoid a definition that relies on itself.

r? `@GuillaumeGomez`
2022-11-22 01:26:06 -05:00
David Tolnay
70cee5af4b
Touch up Box<T> one-liner 2022-11-21 15:28:41 -08:00
Matthias Krüger
9a9569698b
Rollup merge of - tshepang:grammar, r=Mark-Simulacrum
replace unusual grammar
2022-11-20 23:50:29 +01:00
Matthias Krüger
b4513ce6f8
Rollup merge of - zachs18:rc_get_unchecked_mut_docs_soundness, r=Mark-Simulacrum
Clarify and restrict when `{Arc,Rc}::get_unchecked_mut` is allowed.

(Tracking issue for `{Arc,Rc}::get_unchecked_mut`: )

(I'm using `Rc` in this comment, but it applies for `Arc` all the same).

As currently documented, `Rc::get_unchecked_mut` can lead to unsoundness when multiple `Rc`/`Weak` pointers to the same allocation exist. The current documentation only requires that other `Rc`/`Weak` pointers to the same allocation "must not be dereferenced for the duration of the returned borrow". This can lead to unsoundness in (at least) two ways: variance, and `Rc<str>`/`Rc<[u8]>` aliasing. ([playground link](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=d7e2d091c389f463d121630ab0a37320)).

This PR changes the documentation of `Rc::get_unchecked_mut` to restrict usage to when all `Rc<T>`/`Weak<T>` have the exact same `T` (including lifetimes). I believe this is sufficient to prevent unsoundness, while still allowing `get_unchecked_mut` to be called on an aliased `Rc` as long as the safety contract is upheld by the caller.

## Alternatives

* A less strict, but still sound alternative would be to say that the caller must only write values which are valid for all aliased `Rc`/`Weak` inner types. (This was [mentioned](https://github.com/rust-lang/rust/issues/63292#issuecomment-568284090) in the tracking issue). This may be too complicated to clearly express in the documentation.
* A more strict alternative would be to say that there must not be any aliased `Rc`/`Weak` pointers, i.e. it is required that get_mut would return `Some(_)`. (This was also mentioned in the tracking issue). There is at least one codebase that this would cause to become unsound ([here](be5a164d77/src/memtable.rs (L166)), where additional locking is used to ensure unique access to an aliased `Rc<T>`;  I saw this because it was linked on the tracking issue).
2022-11-20 23:50:26 +01:00
Ralf Jung
644a5a34dd enable fuzzy_provenance_casts lint in liballoc 2022-11-20 19:12:18 +01:00
Tshepang Mbambo
bebe5db517 replace unusual grammar 2022-11-20 17:28:34 +02:00
Markus Everling
a1bf25e2bd Update VecDeque implementation 2022-11-20 15:21:16 +01:00
bors
e07425d55b Auto merge of - fee1-dead-contrib:min-deref-patterns, r=compiler-errors
Minimal implementation of implicit deref patterns for Strings

cc `@compiler-errors` `@BoxyUwU` https://github.com/rust-lang/lang-team/issues/88 

~~I forgot to add a feature gate, will do so in a minute~~ Done
2022-11-20 07:16:42 +00:00
Yuki Okushi
785237d392
Rollup merge of - scottmcm:iter-repeat-n, r=thomcc
`VecDeque::resize` should re-use the buffer in the passed-in element

Today it always copies it for *every* appended element, but one of those clones is avoidable.

This adds `iter::repeat_n` (https://github.com/rust-lang/rust/issues/104434) as the primitive needed to do this.  If this PR is acceptable, I'll also use this in `Vec` rather than its custom `ExtendElement` type & infrastructure that is harder to share between multiple different containers:

101e1822c3/library/alloc/src/vec/mod.rs (L2479-L2492)
2022-11-20 13:15:59 +09:00
Yuki Okushi
e69b84204a
Rollup merge of - yancyribbens:add-copy-to-repeat-description, r=JohnTitor
rustdoc: Add copy to the description of repeat

Small nit, but it's more clear to say `copy` here instead of defining `repeat` in terms of itself.
2022-11-20 13:15:58 +09:00
Zachary S
734f724472 Change undefined-behavior doctests from ignore to no_run. 2022-11-18 12:50:41 -06:00
zachs18
f542b068f2 Apply suggestions from code review
Fix spelling error.
2022-11-18 12:50:41 -06:00
Zachary S
8c38cb7709 Add examples to show when {Arc,Rc}::get_mut_unchecked is disallowed. 2022-11-18 12:50:41 -06:00
Zachary S
96650fc714 Clarify and restrict when {Arc,Rc}::get_mut_unchecked is allowed. 2022-11-18 12:50:41 -06:00
clubby789
27019f10ae Remove Vec/Rc storage reuse opt 2022-11-18 10:39:50 +00:00
Deadbeef
64a17a09a8 Rm diagnostic item, use lang item 2022-11-18 06:16:20 +00:00
Deadbeef
b2cb42d6a7 Minimal implementation of implicit deref patterns 2022-11-17 12:46:43 +00:00
bors
36db030a7c Auto merge of - clubby789:grow-rc, r=thomcc
Attempt to reuse `Vec<T>` backing storage for `Rc/Arc<[T]>`

If a `Vec<T>` has sufficient capacity to store the inner `RcBox<[T]>`, we can just reuse the existing allocation and shift the elements up, instead of making a new allocation.
2022-11-17 10:48:22 +00:00
The 8472
c37e8fae57 generalize str.contains() tests to a range of haystack sizes
The Big-O is cubic, but this is only called with ~70 chars so it's still fast enough
2022-11-15 18:30:07 +01:00
Scott McMurray
d62b903892 VecDeque::resize should re-use the buffer in the passed-in element
Today it always copies it for *every* appended element, but one of those clones is avoidable.
2022-11-15 00:53:26 -08:00
The 8472
467b299e53 update str.contains benchmarks 2022-11-14 23:03:16 +01:00
The 8472
4844e5162c black_box test strings in str.contains(str) benchmarks 2022-11-14 23:01:25 +01:00
yancy
f4ffdbfaad rustdoc: Add copy to the description of repeat 2022-11-14 15:21:02 +01:00
clubby789
8424c24837 Add Vec storage optimization to Arc and add tests 2022-11-14 02:30:18 +00:00
clubby789
1c813c4d11 Reuse Vec<T> backing storage for Rc<[T]>
Co-authored-by: joboet <jonas.boettiger@icloud.com>
2022-11-14 01:15:18 +00:00
bors
338cfd3cce Auto merge of - Mark-Simulacrum:bump-bootstrap, r=pietroalbini
Bump bootstrap compiler to 1.66

This PR:

- Bumps version placeholders to release
- Bumps to latest beta
- cfg-steps code

r? `@pietroalbini`
2022-11-14 00:07:19 +00:00
Guillaume Gomez
53b6a894ca
Rollup merge of - RalfJung:miri-alloc-benches, r=thomcc
run alloc benchmarks in Miri and fix UB

Miri since recently has a "fake monotonic clock" that works even with isolation. Its measurements are not very meaningful but it means we can run these benches and check them for UB.

And that's a good thing since there was UB here: fixes https://github.com/rust-lang/rust/issues/104096.

r? ``@thomcc``
2022-11-08 20:40:50 +01:00
Guillaume Gomez
afaba1997d
Rollup merge of - RalfJung:test-sizes, r=thomcc
disable btree size tests on Miri

Seems fine not to run these in Miri, they can't have UB anyway. And this lets us do layout randomization in Miri.

r? ``@thomcc``
2022-11-08 20:40:49 +01:00
Ralf Jung
29d451ccb3 fmt 2022-11-07 15:24:49 +01:00
Dylan DPC
81b8db2675
Rollup merge of - wanghaha-dev:master, r=Dylan-DPC
Modify comment syntax error

Modify comment syntax error
2022-11-07 18:35:26 +05:30