Implement RFC 3107: `#[derive(Default)]` on enums with a `#[default]` attribute
This PR implements RFC 3107, which permits `#[derive(Default)]` on enums where a unit variant has a `#[default]` attribute. See comments for current status.
Stabilize `const_fn_transmute`, `const_fn_union`
This PR stabilizes the `const_fn_transmute` and `const_fn_union` features. It _does not_ stabilize any methods (obviously aside from `transmute`) that are blocked on only these features.
Closes#53605. Closes#51909.
Combine two loops in `check_match`
Suggested by Nadrieril in
https://github.com/rust-lang/rust/pull/79051#discussion_r548778186.
Opening to get a perf run. Hopefully this code doesn't require everything in the
first loop to be done before running the second! (It shouldn't though.)
cc `@Nadrieril`
Update books
## nomicon
1 commits in 7a13537f96af4b9b8e3ea296d6e5c3c7ab72ce9f..f51734eb5566c826b471977747ea3d7d6915bbe9
2021-07-05 23:34:47 -0400 to 2021-07-23 18:24:35 +0900
- Add cloning example for dot operator behaviour (rust-lang/nomicon#292)
## reference
3 commits in 82d75cf423e4a7824fb36e73ccb18519d6900610..3b7be075af5d6e402a18efff672a8a265b4596fd
2021-07-15 06:49:08 -0700 to 2021-07-26 13:20:11 -0700
- Fix typos + grammar (rust-lang/reference#1037)
- Expand on Unicode identifiers. (rust-lang/reference#1022)
- Remove incorrect apostrophe (rust-lang/reference#1076)
## book
17 commits in eac55314210519238652f12b30fec9daea61f7fe..a07036f864b37896b31eb996cd7aedb489f69a1f
2021-07-19 11:08:01 -0400 to 2021-07-26 20:19:46 -0400
- Set expectations a bit more realistically
- Snapshot of chapter 4 for nostarch
- A few small wording tweaks in ch 4
- Clarify that it's not stack/heap exactly that matters for copy/non copy, fixesrust-lang/book#2799
- Clarify a detail around move. Fixesrust-lang/book#2413.
- Clarify places that changed because of NLL. Fixesrust-lang/book#1939.
- nostarch ch3
- Small edits to chapter 3
- (rust-lang/book#2797)
- Update ch03-03-how-functions-work.md: Pervasive -> Prevalent. (rust-lang/book#2796)
- Address loop labels and continue. Fixesrust-lang/book#1392.
- Clarify behavior of integer division. Fixesrust-lang/book#2248.
- Demonstrate how scope interacts with shadowing
- Add another cross-reference to the new unit type introduction
- Introduce the unit type with tuples. Fixesrust-lang/book#1933.
- Reword sentence to not have numbers separated only by a comma
- Link directly to other installation page. Fixesrust-lang/book#1609
## rust-by-example
1 commits in 1db6bb483cc87ad3b424d9aba764fe622960a1be..0dc9cd4e89f00cb5230f120e1a083916386e422b
2021-07-15 06:17:42 -0300 to 2021-07-23 09:14:27 -0300
- Grammatical mistake: Comparison as ... as the (rust-lang/rust-by-example#1453)
## rustc-dev-guide
2 commits in 93422c21baca585dc88357ec886a48f6ddc7d665..09343d6f921d2a07c66f8c41ec3d65bf1fa52556
2021-07-13 12:45:58 -0400 to 2021-07-26 00:37:28 +0200
- Fix typo in building/bootstrapping.md (rust-lang/rustc-dev-guide#1175)
- Link directly to stabilization report comments (rust-lang/rustc-dev-guide#1173)
## edition-guide
4 commits in af696ce8ea526445590ae0ca66a8128d2a95a69a..3710b0cae783d0bcd2b42452a63b081473f5970a
2021-07-20 11:38:03 -0400 to 2021-07-26 11:34:46 -0700
- Add more consistent headings and add a migration section to reserving-syntax (rust-lang/edition-guide#263)
- reserving-syntax.md: Expand and add detail (rust-lang/edition-guide#249)
- Fix typo in or-patterns section (rust-lang/edition-guide#262)
- Fix typo (rust-lang/edition-guide#261)
get rid of NoMirFor error variant
The only place where we throw that error, it is very quickly caught again and turned into a different error. So raise that other error immediately.
Update VxWork's UNIX support
1. VxWorks does not provide glibc
2. VxWorks does provide `sigemptyset` and `sigaddset`
Note: these changes are concurrent to [this PR](https://github.com/rust-lang/libc/pull/2295) in libc.
Add flag to configure `large_assignments` lint
The `large_assignments` lints detects moves over specified limit. The
limit is configured through `move_size_limit = "N"` attribute placed at
the root of a crate. When attribute is absent, the lint is disabled.
Make it possible to enable the lint without making any changes to the
source code, through a new flag `-Zmove-size-limit=N`. For example, to
detect moves exceeding 1023 bytes in a cargo crate, including all
dependencies one could use:
```
$ env RUSTFLAGS=-Zmove-size-limit=1024 cargo build -vv
```
Lint tracking issue #83518.
implement fold() on array::IntoIter to improve flatten().collect() perf
With #87168 flattening `array::IntoIter`s is now `TrustedLen`, the `FromIterator` implementation for `Vec` has a specialization for `TrustedLen` iterators which uses internal iteration. This implements one of the main internal iteration methods on `array::Into` to optimize the combination of those two features.
This should address the main issue in #87411
```
# old
test vec::bench_flat_map_collect ... bench: 2,244,024 ns/iter (+/- 18,903)
# new
test vec::bench_flat_map_collect ... bench: 172,863 ns/iter (+/- 2,141)
```
Remove unstable `--pretty` flag
It doesn't do anything `--unpretty` doesn't, and due to a bug, also
didn't show up in `--help`. I don't think there's any reason to keep it
around, I haven't seen anyone using it.
Closes https://github.com/rust-lang/rust/issues/36473.
Make StrSearcher behave correctly on empty needle
Fix#85462.
This will not affect ABI since the other variant of the enum is bigger.
It may break some code, but that would be very strange: usually people
don't continue after the first `Done` (or `None` for a normal iterator).
`@rustbot` label T-libs A-str A-patterns
Rollup of 8 pull requests
Successful merges:
- #87436 (Suggest `;` on parse error where applicable)
- #87444 (Flatten nested `format!` calls)
- #87447 (Miri: santiy check that null pointer can never have an AllocId)
- #87457 (freebsd remove compiler workaround.)
- #87458 (Fix help message for modification to &T created by &{t})
- #87464 (Remove unnecessary `structhead` parameter from `render_union`)
- #87473 (Notify the Rust 2021 edition working group in zulip of edition bugs)
- #87474 (Add missing whitespace after attribute in HTML template)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
2229: Don't capture preicese paths on top of a union
- Accessing fields of a union require unsafe block
- As part of 2229 we don't allow precision where we need an unsafe block
to capture.
Fixes: #87378
r? `@nikomatsakis`
Add missing whitespace after attribute in HTML template
Firefox (even though it worked) highlights it as red when you look at the source code because there is a missing whitespace.
r? `@notriddle`
Notify the Rust 2021 edition working group in zulip of edition bugs
Notifying the group of these issues will make it easier for us to track them.
r? `@jyn514`
Remove unnecessary `structhead` parameter from `render_union`
`structhead` is used for `render_struct` so that the logic for rendering
structs can be shared between struct variants and struct items. However,
`render_union` is not used anywhere except for rendering union items, so
its `structhead` parameter is unnecessary.
Fix help message for modification to &T created by &{t}
Previous:
```rust
error[E0594]: cannot assign to `*x` which is behind a `&` reference
--> src/main.rs:3:5
|
2 | let x: &usize = &mut{0};
| ------- help: consider changing this to be a mutable reference: `&mut mut{0}`
3 | *x = 1;
| ^^^^^^ `x` is a `&` reference, so the data it refers to cannot be written
```
