Rust 1.53.0

Language

-----------------------

- [You can now use unicode for identifiers.][83799] This allows multilingual

identifiers but still doesn't allow glyphs that are not considered characters

such as ◆ or 🦀. More specifically you can now use any identifier that

matches the UAX #31 "Unicode Identifier and Pattern Syntax" standard. This

is the same standard as languages like Python, however Rust uses NFC

normalization which may be different from other languages.

- [You can now specify "or patterns" inside pattern matches.][79278]

Previously you could only use | (OR) on complete patterns. E.g.

  let x = Some(2u8);
// Before
matches!(x, Some(1) | Some(2));
// Now
matches!(x, Some(1 | 2));

- [Added the :pat_param macro_rules! matcher.][83386] This matcher

has the same semantics as the :pat matcher. This is to allow :pat

to change semantics to being a pattern fragment in a future edition.

Compiler

-----------------------

- [Updated the minimum external LLVM version to LLVM 10.][83387]

- [Added Tier 3\* support for the wasm64-unknown-unknown target.][80525]

- [Improved debuginfo for closures and async functions on Windows MSVC.][83941]

\* Refer to Rust's [platform support page][platform-support-doc] for more

information on Rust's tiered platform support.

Libraries

-----------------------

- [Abort messages will now forward to android_set_abort_message on

Android platforms when available.][81469]

- [slice::IterMut<'_, T> now implements AsRef<[T]>][82771]

- [Arrays of any length now implement IntoIterator.][84147]

Currently calling .into_iter() as a method on an array will

return impl Iterator, but this may change in a

future edition to change Item to T. Calling IntoIterator::into_iter

directly on arrays will provide impl Iterator as expected.

- [leading_zeros, and trailing_zeros are now available on all

NonZero integer types.][84082]

- [{f32, f64}::from_str now parse and print special values

(NaN, -0) according to IEEE 754.][78618]

- [You can now index into slices using (Bound, Bound).][77704]

- [Add the BITS associated constant to all numeric types.][82565]

Stabilised APIs

---------------

- [AtomicBool::fetch_update]

- [AtomicPtr::fetch_update]

- [BTreeMap::retain]

- [BTreeSet::retain]

- [BufReader::seek_relative]

- [DebugStruct::non_exhaustive]

- [Duration::MAX]

- [Duration::ZERO]

- [Duration::is_zero]

- [Duration::saturating_add]

- [Duration::saturating_mul]

- [Duration::saturating_sub]

- [ErrorKind::Unsupported]

- [Option::insert]

- [Ordering::is_eq]

- [Ordering::is_ge]

- [Ordering::is_gt]

- [Ordering::is_le]

- [Ordering::is_lt]

- [Ordering::is_ne]

- [OsStr::is_ascii]

- [OsStr::make_ascii_lowercase]

- [OsStr::make_ascii_uppercase]

- [OsStr::to_ascii_lowercase]

- [OsStr::to_ascii_uppercase]

- [Peekable::peek_mut]

- [Rc::decrement_strong_count]

- [Rc::increment_strong_count]

- [Vec::extend_from_within]

- [array::from_mut]

- [array::from_ref]

- [cmp::max_by_key]

- [cmp::max_by]

- [cmp::min_by_key]

- [cmp::min_by]

- [f32::is_subnormal]

- [f64::is_subnormal]

Cargo

-----------------------

- [Cargo now supports git repositories where the default HEAD branch is not

"master".][cargo/9392] This also includes a switch to the version 3 Cargo.lock format

which can handle default branches correctly.

- [macOS targets now default to unpacked split-debuginfo.][cargo/9298]

- [The authors field is no longer included in Cargo.toml for new

projects.][cargo/9282]

Rustdoc

-----------------------

- [Added the rustdoc::bare_urls lint that warns when you have URLs

without hyperlinks.][81764]

Compatibility Notes

-------------------

- [Implement token-based handling of attributes during expansion][82608]

- [Ipv4::from_str will now reject octal format IP addresses in addition

to rejecting hexadecimal IP addresses.][83652] The octal format can lead

to confusion and potential security vulnerabilities and [is no

longer recommended][ietf6943].

- [The added BITS constant may conflict with external definitions.][85667]

In particular, this was known to be a problem in the lexical-core crate,

but they have published fixes for semantic versions 0.4 through 0.7. To

update this dependency alone, use cargo update -p lexical-core.

- Incremental compilation remains off by default, unless one uses the RUSTC_FORCE_INCREMENTAL=1 environment variable added in 1.52.1.

Internal Only

-------------

These changes provide no direct user facing benefits, but represent significant

improvements to the internals and overall performance of rustc and

related tools.

- [Rework the std::sys::windows::alloc implementation.][83065]

- [rustdoc: Don't enter an infer_ctxt in get_blanket_impls for impls that aren't blanket impls.][82864]

- [rustdoc: Only look at blanket impls in get_blanket_impls][83681]

- [Rework rustdoc const type][82873]

[85667]: https://github.com/rust-lang/rust/pull/85667

[83386]: https://github.com/rust-lang/rust/pull/83386

[82771]: https://github.com/rust-lang/rust/pull/82771

[84147]: https://github.com/rust-lang/rust/pull/84147

[84082]: https://github.com/rust-lang/rust/pull/84082

[83799]: https://github.com/rust-lang/rust/pull/83799

[83681]: https://github.com/rust-lang/rust/pull/83681

[83652]: https://github.com/rust-lang/rust/pull/83652

[83387]: https://github.com/rust-lang/rust/pull/83387

[82873]: https://github.com/rust-lang/rust/pull/82873

[82864]: https://github.com/rust-lang/rust/pull/82864

[82608]: https://github.com/rust-lang/rust/pull/82608

[82565]: https://github.com/rust-lang/rust/pull/82565

[80525]: https://github.com/rust-lang/rust/pull/80525

[79278]: https://github.com/rust-lang/rust/pull/79278

[78618]: https://github.com/rust-lang/rust/pull/78618

[77704]: https://github.com/rust-lang/rust/pull/77704

[83941]: https://github.com/rust-lang/rust/pull/83941

[83065]: https://github.com/rust-lang/rust/pull/83065

[81764]: https://github.com/rust-lang/rust/pull/81764

[81469]: https://github.com/rust-lang/rust/pull/81469

[cargo/9298]: https://github.com/rust-lang/cargo/pull/9298

[cargo/9282]: https://github.com/rust-lang/cargo/pull/9282

[cargo/9392]: https://github.com/rust-lang/cargo/pull/9392

[AtomicBool::fetch_update]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicBool.html#method.fetch_update

[AtomicPtr::fetch_update]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicPtr.html#method.fetch_update

[BTreeMap::retain]: https://doc.rust-lang.org/std/collections/struct.BTreeMap.html#method.retain

[BTreeSet::retain]: https://doc.rust-lang.org/std/collections/struct.BTreeSet.html#method.retain

[BufReader::seek_relative]: https://doc.rust-lang.org/std/io/struct.BufReader.html#method.seek_relative

[DebugStruct::non_exhaustive]: https://doc.rust-lang.org/std/fmt/struct.DebugStruct.html#method.finish_non_exhaustive

[Duration::MAX]: https://doc.rust-lang.org/std/time/struct.Duration.html#associatedconstant.MAX

[Duration::ZERO]: https://doc.rust-lang.org/std/time/struct.Duration.html#associatedconstant.ZERO

[Duration::is_zero]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.is_zero

[Duration::saturating_add]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.saturating_add

[Duration::saturating_mul]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.saturating_mul

[Duration::saturating_sub]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.saturating_sub

[ErrorKind::Unsupported]: https://doc.rust-lang.org/std/io/enum.ErrorKind.html#variant.Unsupported

[Option::insert]: https://doc.rust-lang.org/std/option/enum.Option.html#method.insert

[Ordering::is_eq]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.is_eq

[Ordering::is_ge]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.is_ge

[Ordering::is_gt]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.is_gt

[Ordering::is_le]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.is_le

[Ordering::is_lt]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.is_lt

[Ordering::is_ne]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.is_ne

[OsStr::is_ascii]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html#method.is_ascii

[OsStr::make_ascii_lowercase]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html#method.make_ascii_lowercase

[OsStr::make_ascii_uppercase]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html#method.make_ascii_uppercase

[OsStr::to_ascii_lowercase]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html#method.to_ascii_lowercase

[OsStr::to_ascii_uppercase]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html#method.to_ascii_uppercase

[Peekable::peek_mut]: https://doc.rust-lang.org/std/iter/struct.Peekable.html#method.peek_mut

[Rc::decrement_strong_count]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.decrement_strong_count

[Rc::increment_strong_count]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.increment_strong_count

[Vec::extend_from_within]: https://doc.rust-lang.org/beta/std/vec/struct.Vec.html#method.extend_from_within

[array::from_mut]: https://doc.rust-lang.org/beta/std/array/fn.from_mut.html

[array::from_ref]: https://doc.rust-lang.org/beta/std/array/fn.from_ref.html

[cmp::max_by_key]: https://doc.rust-lang.org/beta/std/cmp/fn.max_by_key.html

[cmp::max_by]: https://doc.rust-lang.org/beta/std/cmp/fn.max_by.html

[cmp::min_by_key]: https://doc.rust-lang.org/beta/std/cmp/fn.min_by_key.html

[cmp::min_by]: https://doc.rust-lang.org/beta/std/cmp/fn.min_by.html

[f32::is_subnormal]: https://doc.rust-lang.org/std/primitive.f32.html#method.is_subnormal

[f64::is_subnormal]: https://doc.rust-lang.org/std/primitive.f64.html#method.is_subnormal

[ietf6943]: https://datatracker.ietf.org/doc/html/rfc6943#section-3.1.1