- New infcx usage (rust-lang/rustc-dev-guide#1571)
- Create a chapter for AST validation (rust-lang/rustc-dev-guide#1524)
- Use ephemeral PAT for linkcheck (rust-lang/rustc-dev-guide#1569)
- add section for the new trait solver (rust-lang/rustc-dev-guide#1551)
- version 5 is now not supported (rust-lang/rustc-dev-guide#1568)
- there are still no locale bundles (rust-lang/rustc-dev-guide#1567)
- bumpt date-check examples to current month (rust-lang/rustc-dev-guide#1566)
- Update hir.md (rust-lang/rustc-dev-guide#1565)
- rustc_typeck exists no more (rust-lang/rustc-dev-guide#1559)
- Correct tests misplacement (rust-lang/rustc-dev-guide#1564)
- Update resolution.md (rust-lang/rustc-dev-guide#1561)
- Update asm.md (rust-lang/rustc-dev-guide#1560)
bors [Mon, 30 Jan 2023 17:01:29 +0000 (17:01 +0000)]
Auto merge of #107472 - matthiaskrgr:rollup-s9gn4n7, r=matthiaskrgr
Rollup of 7 pull requests
Successful merges:
- #107125 (Add and use expect methods to hir.)
- #107172 (Reimplement NormalizeArrayLen based on SsaLocals)
- #107177 (Keep all theme-updating logic together)
- #107424 (Make Vec::clone_from and slice::clone_into share the same code)
- #107455 (use a more descriptive name)
- #107465 (`has_allow_dead_code_or_lang_attr` micro refactor)
- #107469 (Change turbofish context link to an archive link)
Matthias Krüger [Mon, 30 Jan 2023 16:50:12 +0000 (17:50 +0100)]
Rollup merge of #107469 - LLBlumire:master, r=jyn514
Change turbofish context link to an archive link
The original tweet in the chain linked to (via quote tweet), and thus the through line of links back to Anna's tweet where she named the turbofish (https://web.archive.org/web/20210911061514/https://twitter.com/whoisaldeka/status/914914008225816576) are lost as the user whoisaldeka has deleted their twitter account.
Switching to an archive link preserves this through line, allowing someone to browse back to see the point at which Anna created the turbofish, as was the original intent of including this context.
I was sharing this test with some friends as I often do, and noticed the changes (I had only seen the version from before her death previously). Looking for context myself, I realized the deleted twitter account was breaking an important link in the chain for the context of who Anna was to begin with, and the exact moment the turbofish was so named.
As an alternative to using an archive, we could link to both the tweet where Anna names the turbofish, and the tweet where she refers to herself as its guardian, as two separate links - not requiring the quote tweet to connect them.
Matthias Krüger [Mon, 30 Jan 2023 16:50:10 +0000 (17:50 +0100)]
Rollup merge of #107424 - bpeel:clone-into-from-share-code, r=scottmcm
Make Vec::clone_from and slice::clone_into share the same code
In the past, `Vec::clone_from` was implemented using `slice::clone_into`. The code from `clone_into` was later duplicated into `clone_from` in 8725e4c337, which is the commit that adds custom allocator support to Vec. Presumably this was done because the `slice::clone_into` method only works for vecs with the default allocator so it would have the wrong type to clone into `Vec<T, A>`.
Later on in 361398009be6 the code for the two methods diverged because the `Vec::clone_from` version gained a specialization to optimize the case when T is Copy. In order to reduce code duplication and make them both be able to take advantage of this specialization, this PR moves the specialization into the slice module and makes vec use it again.
Matthias Krüger [Mon, 30 Jan 2023 16:50:09 +0000 (17:50 +0100)]
Rollup merge of #107177 - thanatos:fix-doc-errant-light-theme, r=notriddle
Keep all theme-updating logic together
Prior to this PR, if the page is restored from the browser bfcache¹, we call `switchToSavedTheme`. But `switchToSavedTheme` never looks at the `use-system-theme` preference. Further, if it can't find a saved theme, it will fall back to the default of "light".
For a user with cookies disabled² whose preferred color scheme is dark, this means the theme will wobble back and forth between dark and light. The sequence that occurs is,
1. The page is loaded. During a page load, we consult `use-system-theme`: as cookies are disabled, this preference is unset. The default is true.
Because the default is true, we look at the preferred color scheme: for our example user, that's "dark". **The page theme is set to dark.** We'll attempt to store these preferences in localStorage, but fail due to cookies being disabled.
2. The user navigates through the docs. Subsequent page loads happen, and the same process in step 1 recurs. Previous pages are (potentially) put into the bfcache.
3. The user navigates backwards/forwards, causing a page in bfcache to be pulled out of cache. The `pageShow` event handler is triggered. However, this calls `switchToSavedTheme`: this doesn't consider the system theme, as noted above. Instead, it only looks for a saved theme. However, with cookies disabled, there is none. It defaults to light. **The page theme is set to light!** The user wonders why the dark theme is lost.
There are effectively two functions trying to determine and apply the correct theme: `updateSystemTheme` and `switchToSavedTheme`. Thus, we merge them into just one: `updateTheme`. This function contains all the logic for determining the correct theme, and is called in all circumstances where we need to set the theme:
* The initial page load
* If the browser preferred color scheme (i.e., light/dark mode) is changed
* If the page is restored from bfcache
* If the user updates the theme preferences (i.e., in `settings.js`)
¹bfcache: https://web.dev/bfcache/ The bfcache is used to sleep a page, if the user navigates away from it, and to restore it from cache if the user returns to it.
²Note that the browser preference that enables/disables cookies really controls many forms of storage. The same preference thus also affects localStorage. (This is so a normal browser user doesn't need to understand the distinction between "cookies" and "localStorage".)
Lucille Blumire [Mon, 30 Jan 2023 14:22:41 +0000 (14:22 +0000)]
Update bastion-of-the-turbofish.rs
The original tweet in the chain linked to, and thus the through line of links back to Anna's tweet where she named the turbofish (https://web.archive.org/web/20210911061514/https://twitter.com/whoisaldeka/status/914914008225816576) are lost as the user whoisaldeka has deleted their twitter account.
Switching to an archive link preserves this through line, allowing someone to browse back to see the point at which Anna created the turbofish, as was the original intent of including this context.
bors [Mon, 30 Jan 2023 13:56:40 +0000 (13:56 +0000)]
Auto merge of #107080 - Urgau:cleanup-bootstrap-extra-check-cfgs, r=Mark-Simulacrum
bootstrap: cleanup the list of extra check cfgs
This PR performs some cleanups on the `EXTRA_CHECK_CFGS` list in bootstrap.
- `target_os=watchos`: no longer relevant because there are now proper targets `*-apple-watchos`
- `target_arch=nvptx64`: target `nvptx64-nvidia-cuda` makes it useless
- `target_arch=le32`: target was removed (https://github.com/rust-lang/rust/pull/45041)
- `release`: was removed from rustfmt (https://github.com/rust-lang/rustfmt/pull/5375 and https://github.com/rust-lang/rustfmt/pull/5449)
- `dont_compile_me`: was removed from stdarch (https://github.com/rust-lang/stdarch/pull/1308)
Also made some external cfg exception mode clear and only activated for rustc and rustc tools (as to not have the Standard Library unintentionally depend on them).
bors [Mon, 30 Jan 2023 11:14:21 +0000 (11:14 +0000)]
Auto merge of #107463 - Dylan-DPC:rollup-6mq1li8, r=Dylan-DPC
Rollup of 6 pull requests
Successful merges:
- #101569 (Don't re-export private/unstable ArgumentV1 from `alloc`.)
- #106106 (Pass `branch.{branch}.remote=origin` to `git submodule update`)
- #107146 (Make `unsizing_params_for_adt` into a query)
- #107264 (Add option to include private items in library docs)
- #107452 (Fix typo in `{Rc, Arc}::get_mut_unchecked` docs)
- #107459 (end entry paragraph with a period (.))
Dylan DPC [Mon, 30 Jan 2023 09:41:46 +0000 (15:11 +0530)]
Rollup merge of #107264 - ferrocene:pa-private-items, r=Mark-Simulacrum
Add option to include private items in library docs
I need to perform some one-off analysis on libcore, and I wanted to use the unstable JSON rustdoc output to easily do it. Unfortunately, there is currently no way to include unstable items in the library docs. This PR adds support for that, with the off-by-default `build.library-docs-private-items` setting.
Dylan DPC [Mon, 30 Jan 2023 09:41:44 +0000 (15:11 +0530)]
Rollup merge of #101569 - m-ou-se:alloc-no-rexport-argumentv1, r=thomcc
Don't re-export private/unstable ArgumentV1 from `alloc`.
The `alloc::fmt::ArgumentV1` re-export was marked as `#[stable]` even though the original `core::fmt::ArgumentV1` is `#[unstable]` (and `#[doc(hidden)]`).
(It wasn't usable though:
```
error[E0658]: use of unstable library feature 'fmt_internals': internal to format_args!
--> src/main.rs:4:12
|
4 | let _: alloc::fmt::ArgumentV1 = todo!();
| ^^^^^^^^^^^^^^^^^^^^^^
|
= help: add `#![feature(fmt_internals)]` to the crate attributes to enable
```
)
Roy Wellington Ⅳ [Sat, 21 Jan 2023 23:21:43 +0000 (18:21 -0500)]
Keep all theme-updating logic together
Prior to this PR, if the page is restored from the browser bfcache¹, we
call `switchToSavedTheme`. But `switchToSavedTheme` never looks at the
`use-system-theme` preference. Further, if it can't find a saved theme,
it will fall back to the default of "light".
For a user with cookies disabled² whose preferred color scheme is dark,
this means the theme will wobble back and forth between dark and light.
The sequence that occurs is,
1. The page is loaded. During a page load, we consult
`use-system-theme`: as cookies are disabled, this preference is
unset. The default is true.
Because the default is true, we look at the preferred color scheme:
for our example user, that's "dark". **The page theme is set to
dark.** We'll attempt to store these preferences in localStorage, but
fail due to cookies being disabled.
2. The user navigates through the docs. Subsequent page loads happen,
and the same process in step 1 recurs. Previous pages are
(potentially) put into the bfcache.
3. The user navigates backwards/forwards, causing a page in bfcache to
be pulled out of cache. The `pageShow` event handler is triggered.
However, this calls `switchToSavedTheme`: this doesn't consider the
system theme, as noted above. Instead, it only looks for a saved
theme. However, with cookies disabled, there is none. It defaults to
light. **The page theme is set to light!** The user wonders why the
dark theme is lost.
There are effectively two functions trying to determine and apply the
correct theme: `updateSystemTheme` and `switchToSavedTheme`. Thus, we
merge them into just one: `updateTheme`. This function contains all the
logic for determining the correct theme, and is called in all
circumstances where we need to set the theme:
* The initial page load
* If the browser preferred color scheme (i.e., light/dark mode) is
changed
* If the page is restored from bfcache
* If the user updates the theme preferences (i.e., in `settings.js`)
Fixes #94250.
¹bfcache: https://web.dev/bfcache/ The bfcache is used to sleep a page,
if the user navigates away from it, and to restore it from cache if the
user returns to it.
²Note that the browser preference that enables/disables cookies really
controls many forms of storage. The same preference thus also affects
localStorage. (This is so a normal browser user doesn't need to
understand the distinction between "cookies" and "localStorage".)
bors [Mon, 30 Jan 2023 07:02:01 +0000 (07:02 +0000)]
Auto merge of #104429 - nnethercote:more-deriving-on-packed-structs, r=RalfJung
More deriving on packed structs
See [here](https://github.com/rust-lang/rust/pull/104429#issuecomment-1320909245) for the t-lang nomination summary, and [here](https://github.com/rust-lang/rust/pull/104429#issuecomment-1360077895) for the approval.
Currently, deriving on packed structs has some non-trivial limitations,
related to the fact that taking references on unaligned fields is UB.
The current approach to field accesses in derived code:
- Normal case: `&self.0`
- In a packed struct that derives `Copy`: `&{self.0}`
- In a packed struct that doesn't derive `Copy`: `&self.0`
Plus, we disallow deriving any builtin traits other than `Default` for any
packed generic type, because it's possible that there might be
misaligned fields. This is a fairly broad restriction.
Plus, we disallow deriving any builtin traits other than `Default` for most
packed types that don't derive `Copy`. (The exceptions are those where the
alignments inherently satisfy the packing, e.g. in a type with
`repr(packed(N))` where all the fields have alignments of `N` or less
anyway. Such types are pretty strange, because the `packed` attribute is
not having any effect.)
This commit introduces a new, simpler approach to field accesses:
- Normal case: `&self.0`
- In a packed struct: `&{self.0}`
In the latter case, this requires that all fields impl `Copy`, which is
a new restriction. This means that the following example compiles under
the old approach and doesn't compile under the new approach.
```
#[derive(Debug)]
struct NonCopy(u8);
#[derive(Debug)
#[repr(packed)]
struct MyType(NonCopy);
```
(Note that the old approach's support for cases like this was brittle.
Changing the `u8` to a `u16` would be enough to stop it working. So not
much capability is lost here.)
However, the other constraints from the old rules are removed. We can now
derive builtin traits for packed generic structs like this:
```
trait Trait { type A; }
#[derive(Hash)]
#[repr(packed)]
pub struct Foo<T: Trait>(T, T::A);
```
To allow this, we add a `T: Copy` bound in the derived impl and a `T::A:
Copy` bound in where clauses. So `T` and `T::A` must impl `Copy`.
We can now also derive builtin traits for packed structs that don't derive
`Copy`, so long as the fields impl `Copy`:
```
#[derive(Hash)]
#[repr(packed)]
pub struct Foo(u32);
```
This includes types that hand-impl `Copy` rather than deriving it, such as the
following, that show up in winapi-0.2:
```
#[derive(Clone)]
#[repr(packed)]
struct MyType(i32);
impl Copy for MyType {}
```
The new approach is simpler to understand and implement, and it avoids
the need for the `unsafe_derive_on_repr_packed` check.
One exception is required for backwards-compatibility: we allow `[u8]`
fields for now. There is a new lint for this,
`byte_slice_in_packed_struct_with_derive`.
bors [Sun, 29 Jan 2023 22:14:18 +0000 (22:14 +0000)]
Auto merge of #103019 - Kobzol:ci-multistage-python, r=Mark-Simulacrum
Port pgo.sh to Python
This PR ports the `pgo.sh` multi stage build file from bash to Python, to make it easier to add new functionality and gather statistics. Main changes:
1) `pgo.sh` rewritten from Bash to Python. Jump from ~200 Bash LOC to ~650 Python LOC. Bash is, unsurprisingly, more concise for running scripts and binaries.
2) Better logging. Each separate stage is now clearly separated in logs, and the logs can be quickly grepped to find out which stage has completed or failed, and how long it took.
3) Better statistics. At the end of the run, there is now a table that shows the duration of the individual stages, along with a percentual ratio of the total workflow run:
A sample run can be seen [here](https://github.com/rust-lang/rust/actions/runs/3923980164/jobs/6707932029).
I tried to keep the code compatible with Python 3.6 and don't use dependencies, which required me to reimplement some small pieces of functionality (like formatting bytes). I suppose that it shouldn't be so hard to upgrade to a newer Python or install dependencies in the CI container, but I'd like to avoid it if it won't be needed.
The code is in a single file `stage-build.py`, so it's a bit cluttered. I can also separate it into multiple files, although having it in a single file has some benefits. The code could definitely be nicer, but I'm a bit wary of introducing a lot of abstraction and similar stuff, as long as the code is stuffed into a single file.
Currently, the Python pipeline should faithfully mirror the bash pipeline one by one. After this PR, I'd like to try to optimize it, e.g. by caching the LLVM builds on S3.
bors [Sun, 29 Jan 2023 19:29:49 +0000 (19:29 +0000)]
Auto merge of #107451 - matthiaskrgr:rollup-m4ucfu8, r=matthiaskrgr
Rollup of 11 pull requests
Successful merges:
- #96763 (Fix maintainer validation message)
- #106540 (Insert whitespace to avoid ident concatenation in suggestion)
- #106763 (print why a test was ignored if its the only test specified)
- #106769 (libtest: Print why a test was ignored if it's the only test specified.)
- #106798 (Implement `signum` with `Ord`)
- #107006 (Output tree representation on thir-tree)
- #107078 (Update wording of invalid_doc_attributes docs.)
- #107169 (Pass `--locked` to the x test tidy call)
- #107431 (docs: remove colon from time header)
- #107432 (rustdoc: remove unused class `has-srclink`)
- #107448 (When stamp doesn't exist, should say Error, and print path to stamp file)
Matthias Krüger [Sun, 29 Jan 2023 19:03:37 +0000 (20:03 +0100)]
Rollup merge of #107078 - ehuss:invalid_doc_attributes-docs, r=jackh726
Update wording of invalid_doc_attributes docs.
There was a typo in the original docs for `invalid_doc_attributes`. I felt it could use a little rewording to try to clarify the reasoning for the lint. Also, this adds the future-incompatible notice.
Matthias Krüger [Sun, 29 Jan 2023 19:03:37 +0000 (20:03 +0100)]
Rollup merge of #107006 - b-naber:thir-tree, r=jackh726
Output tree representation on thir-tree
The current output of `-Zunpretty=thir-tree` is really cumbersome to work with, using an actual tree representation should make it easier to see what the thir looks like.
Matthias Krüger [Sun, 29 Jan 2023 19:03:36 +0000 (20:03 +0100)]
Rollup merge of #106798 - scottmcm:signum-via-cmp, r=Mark-Simulacrum
Implement `signum` with `Ord`
Rather than needing to do things like #105840 for `signum` too, might as well just implement that method using `Ord`, since it's doing the same "I need `-1`/`0`/`+1`" behaviour that `cmp` is already doing.
This also seems to slightly improve the assembly: <https://rust.godbolt.org/z/5oEEqbxK1>
Matthias Krüger [Sun, 29 Jan 2023 19:03:35 +0000 (20:03 +0100)]
Rollup merge of #106540 - lowr:patch/remove-paren-whitespace, r=cjgillot
Insert whitespace to avoid ident concatenation in suggestion
This PR tweaks the suggestion of removing misplaced parentheses around trait bounds so as to avoid concatenating two identifiers. Although subtle, this should make outputs less surprising especially when applying the `MachineApplicable` suggestions automatically.
bors [Sun, 29 Jan 2023 10:20:25 +0000 (10:20 +0000)]
Auto merge of #106253 - nbdd0121:upcast, r=compiler-errors
Skip possible where_clause_object_safety lints when checking `multiple_supertrait_upcastable`
Fix #106247
To achieve this, I lifted the `WhereClauseReferencesSelf` out from `object_safety_violations` and move it into `is_object_safe` (which is changed to a new query).
bors [Sun, 29 Jan 2023 07:01:58 +0000 (07:01 +0000)]
Auto merge of #107435 - matthiaskrgr:rollup-if5h6yu, r=matthiaskrgr
Rollup of 8 pull requests
Successful merges:
- #106618 (Disable `linux_ext` in wasm32 and fortanix rustdoc builds.)
- #107097 (Fix def-use dominance check)
- #107154 (library/std/sys_common: Define MIN_ALIGN for m68k-unknown-linux-gnu)
- #107397 (Gracefully exit if --keep-stage flag is used on a clean source tree)
- #107401 (remove the usize field from CandidateSource::AliasBound)
- #107413 (make more pleasant to read)
- #107422 (Also erase substs for new infcx in pin move error)
- #107425 (Check for missing space between fat arrow and range pattern)
Matthias Krüger [Sun, 29 Jan 2023 05:14:20 +0000 (06:14 +0100)]
Rollup merge of #107422 - Nilstrieb:erase-the-ice, r=compiler-errors
Also erase substs for new infcx in pin move error
The code originally correctly erased the regions of the type it passed to the newly created infcx. But after the `fn_sig` query was made to return an `EarlyBinder<T>`, some substs that were around were substituted there without erasing their regions. They were then passed into the newly cerated infcx, which caused the ICE.
Fixes #107419
r? compiler-errors who reviewed the original PR adding this diagnostic
Matthias Krüger [Sun, 29 Jan 2023 05:14:18 +0000 (06:14 +0100)]
Rollup merge of #107397 - Teapot4195:issue-107392-fix, r=albertlarsan68
Gracefully exit if --keep-stage flag is used on a clean source tree
Instead of quitting with an obscure No such file or directory error, give the user a clearer and easier to understand error (as well as suggesting a possible cause for the error).
This is the first time I have written rust since 2020, and the first PR I will ever make to rust, so please do point out any mistakes I have made :smile: .
Matthias Krüger [Sun, 29 Jan 2023 05:14:17 +0000 (06:14 +0100)]
Rollup merge of #107097 - tmiasko:ssa, r=cjgillot
Fix def-use dominance check
A definition does not dominate a use in the same statement. For example
in MIR generated for compound assignment x += a (when overflow checks
are disabled).
Matthias Krüger [Sun, 29 Jan 2023 05:14:16 +0000 (06:14 +0100)]
Rollup merge of #106618 - jmillikin:os-net-rustdoc-wasm32, r=JohnTitor
Disable `linux_ext` in wasm32 and fortanix rustdoc builds.
The `std::os::unix` module is stubbed out when building docs for these target platforms. The introduction of Linux-specific extension traits caused `std::os::net` to depend on sub-modules of `std::os::unix`, which broke rustdoc for the `wasm32-unknown-unknown` target.
Adding an additional `#[cfg]` guard solves that rustdoc failure by not declaring `linux_ext` on targets with a stubbed `std::os::unix`.
bors [Sun, 29 Jan 2023 04:11:27 +0000 (04:11 +0000)]
Auto merge of #106227 - bryangarza:ctfe-limit, r=oli-obk
Use stable metric for const eval limit instead of current terminator-based logic
This patch adds a `MirPass` that inserts a new MIR instruction `ConstEvalCounter` to any loops and function calls in the CFG. This instruction is used during Const Eval to count against the `const_eval_limit`, and emit the `StepLimitReached` error, replacing the current logic which uses Terminators only.
The new method of counting loops and function calls should be more stable across compiler versions (i.e., not cause crates that compiled successfully before, to no longer compile when changes to the MIR generation/optimization are made).
bors [Sat, 28 Jan 2023 22:11:11 +0000 (22:11 +0000)]
Auto merge of #103659 - clubby789:improve-partialord-derive, r=nagisa
Special-case deriving `PartialOrd` for enums with dataless variants
I was able to get slightly better codegen by flipping the derived `PartialOrd` logic for two-variant enums. I also tried to document the implementation of the derive macro to make the special-case logic a little clearer.
```rs
#[derive(PartialEq, PartialOrd)]
pub enum A<T> {
A,
B(T)
}
```
```diff
impl<T: ::core::cmp::PartialOrd> ::core::cmp::PartialOrd for A<T> {
#[inline]
fn partial_cmp(
&self,
other: &A<T>,
) -> ::core::option::Option<::core::cmp::Ordering> {
let __self_tag = ::core::intrinsics::discriminant_value(self);
let __arg1_tag = ::core::intrinsics::discriminant_value(other);
- match ::core::cmp::PartialOrd::partial_cmp(&__self_tag, &__arg1_tag) {
- ::core::option::Option::Some(::core::cmp::Ordering::Equal) => {
- match (self, other) {
- (A::B(__self_0), A::B(__arg1_0)) => {
- ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0)
- }
- _ => ::core::option::Option::Some(::core::cmp::Ordering::Equal),
- }
+ match (self, other) {
+ (A::B(__self_0), A::B(__arg1_0)) => {
+ ::core::cmp::PartialOrd::partial_cmp(__self_0, __arg1_0)
}
- cmp => cmp,
+ _ => ::core::cmp::PartialOrd::partial_cmp(&__self_tag, &__arg1_tag),
}
}
}
```
Godbolt: [Current](https://godbolt.org/z/GYjEzG1T8), [New](https://godbolt.org/z/GoK78qx15)
I'm not sure how common a case comparing two enums like this (such as `Option`) is, and if it's worth the slowdown of adding a special case to the derive. If it causes overall regressions it might be worth just manually implementing this for `Option`.
Nilstrieb [Sat, 28 Jan 2023 19:43:16 +0000 (20:43 +0100)]
Also erase substs for new infcx in pin move error
The code originally correctly erased the regions of the type it passed
to the newly created infcx. But after the `fn_sig` query was made to
return an `EarlyBinder<T>`, some substs that were around were
substituted there without erasing their regions. They were then passed
into the newly cerated infcx, which caused the ICE.
Neil Roberts [Sat, 28 Jan 2023 13:52:31 +0000 (14:52 +0100)]
vec: Use SpecCloneIntoVec::clone_into to implement Vec::clone_from
In the past, Vec::clone_from was implemented using slice::clone_into.
The code from clone_into was later duplicated into clone_from in 8725e4c337, which is the commit that adds custom allocator support to
Vec. Presumably this was done because the slice::clone_into only works
for vecs with the default allocator so it would have the wrong type to
clone into Vec<T, A>.
Now that the clone_into implementation is moved out into a specializable
trait anyway we might as well use that to share the code between the two
methods.
Neil Roberts [Sat, 28 Jan 2023 13:19:01 +0000 (14:19 +0100)]
slice: Add a specialization for clone_into when T is Copy
The implementation for the ToOwned::clone_into method on [T] is a copy
of the code for vec::clone_from. In 361398009be6 the code for
vec::clone_from gained a specialization for when T is Copy. This commit
copies that specialization over to the clone_into implementation.
This has been unstably const for over a year now. And the code change simplifying the constness of the `new` constructors has been in stable Rust since 1.64 (a bit over a full release cycle). I'm not aware of any blockers to this stabilization.