Commit Graph

686 Commits

Author SHA1 Message Date
Stein Somers
bb61cc48b3 BTreeMap: offer merge in variants with more clarity 2021-01-16 18:56:03 +01:00
bors
efdb859dcd Auto merge of #80873 - ssomers:btree_cleanup_slices_4, r=Mark-Simulacrum
BTreeMap: tougher checks on code using raw into_kv_pointers

r? `@Mark-Simulacrum`
2021-01-16 07:12:12 +00:00
Yuki Okushi
1b8fd02daa
Rollup merge of #80834 - bugadani:vecdeque, r=oli-obk
Remove unreachable panics from VecDeque::{front/back}[_mut]

`VecDeque`'s `front`, `front_mut`, `back` and `back_mut` methods are implemented in terms of the index operator, which causes these functions to contain [unreachable panic calls](https://rust.godbolt.org/z/MTnq1o).

This PR reimplements these methods in terms of `get[_mut]` instead.
2021-01-15 18:26:11 +09:00
Dániel Buga
744f885e2a Remove unreachable panics from VecDeque 2021-01-14 19:31:56 +01:00
Mara Bos
9bfe6f1b2c
Rollup merge of #80972 - KodrAus:deprecate/remove_item, r=nagisa
Remove unstable deprecated Vec::remove_item

Closes #40062

The `Vec::remove_item` method was deprecated in `1.46.0` (in August of 2020). This PR now removes that unstable method entirely.
2021-01-14 18:00:18 +00:00
Mara Bos
7855a730b9
Rollup merge of #80966 - KodrAus:deprecate/spin_loop_hint, r=m-ou-se
Deprecate atomic::spin_loop_hint in favour of hint::spin_loop

For https://github.com/rust-lang/rust/issues/55002

We wanted to leave `atomic::spin_loop_hint` alone when stabilizing `hint::spin_loop` so folks had some time to migrate. This now deprecates `atomic_spin_loop_hint`.
2021-01-14 18:00:14 +00:00
bors
116d1a7056 Auto merge of #80824 - cuviper:heap-clones, r=kennytm
Try to avoid locals when cloning into Box/Rc/Arc

For generic `T: Clone`, we can allocate an uninitialized box beforehand,
which gives the optimizer a chance to create the clone directly in the
heap. For `T: Copy`, we can go further and do a simple memory copy,
regardless of optimization level.

The same applies to `Rc`/`Arc::make_mut` when they must clone the data.
2021-01-13 11:11:34 +00:00
bors
9f3998b4aa Auto merge of #77858 - ijackson:split-inclusive, r=KodrAus
Stabilize split_inclusive

### Contents of this MR

This stabilises:

 * `slice::split_inclusive`
 * `slice::split_inclusive_mut`
 * `str::split_inclusive`

Closes #72360.

### A possible concern

The proliferation of `split_*` methods is not particularly pretty.  The existence of `split_inclusive` seems to invite the addition of `rsplit_inclusive`, `splitn_inclusive`, etc.  We could instead have a more general API, along these kinds of lines maybe:
```
   pub fn split_generic('a,P,H>(&'a self, pat: P, how: H) -> ...
       where P: Pattern
       where H: SplitHow;

   pub fn split_generic_mut('a,P,H>(&'a mut self, pat: P, how: H) -> ...
       where P: Pattern
       where H: SplitHow;

   trait SplitHow {
       fn reverse(&self) -> bool;
       fn inclusive -> bool;
       fn limit(&self) -> Option<usize>;
   }

   pub struct SplitFwd;
   ...
   pub struct SplitRevInclN(pub usize);
```
But maybe that is worse.

### Let us defer that? ###

This seems like a can of worms.  I think we can defer opening it now; if and when we have something more general, these two methods can become convenience aliases.  But I thought I would mention it so the lang API team can consider it and have an opinion.
2021-01-13 07:38:58 +00:00
Ashley Mannix
d65cb6ebce deprecate atomic::spin_loop_hint in favour of hint::spin_loop 2021-01-13 16:30:29 +10:00
Ashley Mannix
7e83fece91 remove unstable deprecated Vec::remove_item 2021-01-13 15:14:11 +10:00
Josh Stone
1f1a3b4857 move WriteCloneIntoRaw into alloc::alloc 2021-01-12 12:24:28 -08:00
Josh Stone
f89f30fb2c Move directly when Rc/Arc::make_mut splits from Weak
When only other `Weak` references remain, we can directly move the data
into the new unique allocation as a plain memory copy.
2021-01-11 17:46:49 -08:00
Josh Stone
d85df44e8d Specialize Rc/Arc::make_mut clones to try to avoid locals
As we did with `Box`, we can allocate an uninitialized `Rc` or `Arc`
beforehand, giving the optimizer a chance to skip the local value for
regular clones, or avoid any local altogether for `T: Copy`.
2021-01-11 17:43:10 -08:00
Josh Stone
9aa7dd1e6a Specialize Box clones to try to avoid locals
For generic `T: Clone`, we can allocate an uninitialized box beforehand,
which gives the optimizer a chance to create the clone directly in the
heap. For `T: Copy`, we can go further and do a simple memory copy,
regardless of optimization level.
2021-01-11 17:43:10 -08:00
Yuki Okushi
39e1331cfa Add another test case for #79808
Taken from #80293.
2021-01-11 12:10:16 +09:00
Stein Somers
c1dfb4a9c4 BTreeMap: tougher checks on code using raw into_kv_pointers 2021-01-10 14:40:21 +01:00
bors
fd34606ddf Auto merge of #80391 - ssomers:btree_cleanup_slices_3, r=Mark-Simulacrum
BTreeMap: tougher checking on most uses of copy_nonoverlapping

Miri checks pointer provenance and destination, but we can check it in debug builds already.
Also, we can let Miri confirm we don't mistake imprints of moved keys and values as genuine.
r? `@Mark-Simulacrum`
2021-01-10 10:48:55 +00:00
Camelid
befd153098
Add comment to Vec::truncate explaining > vs >=
Hopefully this will prevent people from continuing to ask about this
over and over again :)

See [this Zulip discussion][1] for more.

[1]: https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Vec.3A.3Atruncate.20implementation
2021-01-09 12:35:47 -08:00
Stein Somers
26b94626a1 BTreeMap: tougher checks on most uses of copy_nonoverlapping 2021-01-08 19:58:05 +01:00
bors
b5c496de37 Auto merge of #79863 - JohnTitor:compiler-builtins, r=bjorn3
Update `compiler_builtins` to 0.1.39

This version contains the fixes of https://github.com/rust-lang/compiler-builtins/issues/390 and https://github.com/rust-lang/compiler-builtins/issues/391.
Also, rename features following https://github.com/rust-lang/compiler-builtins/pull/386.
2021-01-07 11:22:42 +00:00
Yuki Okushi
6275a29dbe Update compiler_builtins to 0.1.39 2021-01-07 16:16:36 +09:00
Yuki Okushi
cda26a6b15
Rollup merge of #80666 - jjlin:master, r=Dylan-DPC
Fix missing link for "fully qualified syntax"

This issue can currently be seen at https://doc.rust-lang.org/stable/std/rc/index.html#toggle-all-docs:~:text=%5B-,fully%20qualified%20syntax

It originates from #76138, where the link was added to `library/alloc/src/sync.rs`, but not `library/alloc/src/rc.rs`.
2021-01-05 09:52:47 +09:00
Yuki Okushi
bdf8bbde1d
Rollup merge of #80442 - steffahn:mention_arc_in_cow, r=Mark-Simulacrum
Mention Arc::make_mut and Rc::make_mut in the documentation of Cow

Following this discussion: https://users.rust-lang.org/t/should-the-cow-documentation-mention-arc/53341

_Rendered (the last paragraph is new):_

![Screenshot_20201228_171551](https://user-images.githubusercontent.com/3986214/103228135-5d72e200-4930-11eb-89e1-38b5c86b08c7.png)

`@rustbot` modify labels: T-doc, T-libs
2021-01-05 09:52:33 +09:00
Ian Jackson
be226e49e4 Stabilize split_inclusive
Closes #72360.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
2021-01-04 16:20:08 +00:00
Jeremy Lin
6d45d055a1 Fix missing link for "fully qualified syntax" 2021-01-03 13:59:02 -08:00
Guillaume Gomez
2072e11730
Rollup merge of #80591 - lcnr:incomplete-features, r=RalfJung
remove allow(incomplete_features) from std

cc https://github.com/rust-lang/rust/pull/80349#issuecomment-753357123

> Now I am somewhat concerned that the standard library uses some of these features...

I think it is theoretically ok to use incomplete features in the standard library or the compiler if we know that there is an already working subset and we explicitly document what we have to be careful about. Though at that point it is probably better to try and split the incomplete feature into two separate ones, similar to `min_specialization`.

Will be interesting once `feature(const_evaluatable_checked)` works well enough to imo be used in the compiler but not yet well enough to be removed from `INCOMPLETE_FEATURES`.

r? `@RalfJung`
2021-01-03 17:09:08 +01:00
bors
0876f59b97 Auto merge of #77832 - camelid:remove-manual-link-resolves, r=jyn514
Remove many unnecessary manual link resolves from library

Now that #76934 has merged, we can remove a lot of these! E.g, this is
no longer necessary:

    [`Vec<T>`]: Vec

cc `@jyn514`
2021-01-02 01:31:03 +00:00
Bastian Kauschke
6cf47ff4f0 remove incomplete features from std 2021-01-01 19:57:10 +01:00
bors
18d27b2c94 Auto merge of #80310 - Manishearth:box-try-alloc, r=kennytm
Add fallible Box, Arc, and Rc allocator APIs

cc https://github.com/rust-lang/rust/issues/48043

It was suggested in https://github.com/rust-lang/rust/issues/48043#issuecomment-748008486 that `Box::try_*` follows the spirit of RFC 2116. This PR is an attempt to add the relevant APIs, tied to the same feature gate. Happy to make any changes or turn this into an RFC if necessary.

cc `@rust-lang/wg-allocators`
2021-01-01 10:29:43 +00:00
Camelid
0506789014 Remove many unnecessary manual link resolves from library
Now that #76934 has merged, we can remove a lot of these! E.g, this is
no longer necessary:

    [`Vec<T>`]: Vec
2020-12-31 11:54:32 -08:00
Manish Goregaokar
375e7c5864 More inline, doc fixes 2020-12-31 16:49:44 +00:00
Manish Goregaokar
8f3cb7d75d Make [A]Rc::allocate_for_layout() use try_allocate_for_layout() 2020-12-31 16:36:28 +00:00
bors
b33e234155 Auto merge of #79895 - Kerollmops:slice-group-by, r=m-ou-se
The return of the GroupBy and GroupByMut iterators on slice

According to https://github.com/rust-lang/rfcs/pull/2477#issuecomment-742034372, I am opening this PR again, this time I implemented it in safe Rust only, it is therefore much easier to read and is completely safe.

This PR proposes to add two new methods to the slice, the `group_by` and `group_by_mut`. These two methods provide a way to iterate over non-overlapping sub-slices of a base slice that are separated by the predicate given by the user (e.g. `Partial::eq`, `|a, b| a.abs() < b.abs()`).

```rust
let slice = &[1, 1, 1, 3, 3, 2, 2, 2];

let mut iter = slice.group_by(|a, b| a == b);
assert_eq!(iter.next(), Some(&[1, 1, 1][..]));
assert_eq!(iter.next(), Some(&[3, 3][..]));
assert_eq!(iter.next(), Some(&[2, 2, 2][..]));
assert_eq!(iter.next(), None);
```

[An RFC](https://github.com/rust-lang/rfcs/pull/2477) was open 2 years ago but wasn't necessary.
2020-12-31 12:00:43 +00:00
Clément Renault
8b53be6604
Replace the tracking issue for the slice_group_by feature 2020-12-31 12:13:03 +01:00
Manish Goregaokar
589aa8e29c Reuse Box::try_new_*_in() in Box::new_*_in() 2020-12-31 08:43:30 +00:00
Manish Goregaokar
bb15fa1da0 Add fallible Arc APIs (Arc::try_new_*) 2020-12-31 08:31:55 +00:00
Manish Goregaokar
973fa8e30e Add fallible Rc APIs (Rc::try_new_*) 2020-12-31 08:15:38 +00:00
Manish Goregaokar
dd2c6c318b Add fallible box APIs (Box::try_new_*) 2020-12-31 08:14:38 +00:00
Manish Goregaokar
d116f48788 Add fallible box allocator APIs (Box::try_new_*_in()) 2020-12-31 08:14:38 +00:00
bors
9775ffef2a Auto merge of #80530 - m-ou-se:rollup-zit69ko, r=m-ou-se
Rollup of 9 pull requests

Successful merges:

 - #78934 (refactor: removing library/alloc/src/vec/mod.rs ignore-tidy-filelength)
 - #79479 (Add `Iterator::intersperse`)
 - #80128 (Edit rustc_ast::ast::FieldPat docs)
 - #80424 (Don't give an error when creating a file for the first time)
 - #80458 (Some Promotion Refactoring)
 - #80488 (Do not create dangling &T in Weak<T>::drop)
 - #80491 (Miri: make size/align_of_val work for dangling raw ptrs)
 - #80495 (Rename kw::Invalid -> kw::Empty)
 - #80513 (Add regression test for #80062)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2020-12-30 21:25:15 +00:00
Mara Bos
3d93dfdf6e
Rollup merge of #80488 - CAD97:drop-weak-without-reference, r=m-ou-se
Do not create dangling &T in Weak<T>::drop

Since at this point all strong pointers have been dropped, the wrapped `T` has also been dropped. As such, creating a `&T` to the dropped place is negligent at best (language UB at worst). Since we have `Layout::for_value_raw` now, use that instead of `Layout::for_value` to avoid creating the `&T`.

This does have implications for custom (potentially thin) DSTs, though much less severe than those discussed in #80407. Specifically, one of two things has to be true:

- It has to be possible to use a `*const T` to a dropped (potentially custom, potentially thin) unsized tailed object to determine the layout (size/align) of the object. This is what is currently implemented (though with `&T` instead of `&T`). The validity of reading some location after it has been dropped is an open question IIUC (https://github.com/rust-lang/unsafe-code-guidelines/issues/188) (except when the whole type is `Copy`, per `drop_in_place`'s docs).
  In this design, custom DSTs would get a `*mut T` and use that to return layout, and must be able to do so while in the "zombie" (post-drop, pre-free) state.
- `RcBox`/`ArcInner` compute and store layout eagerly, so that they don't have to ask the type for its layout after dropping it.

Importantly, this is already true today, as you can construct `Rc<DST>`, create a `Weak<DST>`, and drop the `Rc` before the `Weak`. This PR is a strict improvement over the status quo, and the above question about potentially thin DSTs will need to be resolved by any custom DST proposal.
2020-12-30 20:56:54 +00:00
Mara Bos
16834a8f52
Fix rustdoc link in vec/into_iter.rs. 2020-12-30 15:35:02 +00:00
Mark Rousskov
fe031180d0 Bump bootstrap compiler to 1.50 beta 2020-12-30 09:27:19 -05:00
CAD97
81685e9ad8 Do not create dangling &T in Weak<T>::drop 2020-12-29 15:42:41 -05:00
C
f7a6f0cae3 docs: fixing references 2020-12-29 14:03:30 +00:00
C
80f10d7aa7 fix: moved import into #[cfg(test)] 2020-12-29 14:03:30 +00:00
C
2de8356f60 style: applying Rust style 2020-12-29 14:03:30 +00:00
C
6002b280f1 refactor: removing // ignore-tidy-filelength 2020-12-29 14:03:30 +00:00
C
bd49a60f29 refactor: moved SpecExtend into spec_extend.rs 2020-12-29 14:03:30 +00:00
C
d24a27797d refactor: moving SpecFromIter into spec_from_iter.rs 2020-12-29 14:03:30 +00:00