Add initial 1.63.0 announcement

Author: Mark-Simulacrum

posts/2022-08-11-Rust-1.63.0.md

@@ -0,0 +1,142 @@
+---
+layout: post
+title: "Announcing Rust 1.63.0"
+author: The Rust Release Team
+release: true
+---
+
+The Rust team is happy to announce a new version of Rust, 1.63.0. Rust is a programming language
+empowering everyone to build reliable and efficient software.
+
+If you have a previous version of Rust installed via rustup, you can get 1.63.0 with:
+
+```console
+rustup update stable
+```
+
+If you don't have it already, you can [get `rustup`][install]
+from the appropriate page on our website, and check out the
+[detailed release notes for 1.63.0][notes] on GitHub.
+
+If you'd like to help us out by testing future releases, you might consider updating locally to use
+the beta channel (`rustup default beta`) or the nightly channel (`rustup default nightly`).
+Please [report] any bugs you might come across!
+
+[install]: https://www.rust-lang.org/install.html
+[notes]: https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1620-2022-06-30
+[report]: https://github.com/rust-lang/rust/issues/new/choose
+
+## What's in 1.63.0 stable
+
+### Rust ownership for raw file descriptors/handles (I/O Safety)
+
+Previously, Rust code working with platform APIs taking raw file descriptors (on
+unix-style platforms) or handles (on Windows) would typically work directly with
+a platform-specific representation of the descriptor (for example, a `c_int`).
+For Rust bindings to such native APIs, the type system then failed to encode
+whether the API would take ownership of the file descriptor (e.g., `close`) or
+merely borrow it (e.g., `dup`).
+
+Now, Rust provides wrapper types such as [`BorrowedFd`], which are marked as
+`#[repr(transparent)]`, meaning that `extern "C"` bindings can directly take
+these types to encode the ownership semantics. See the stabilized APIs section
+for the full list of wrapper types stabilized in 1.63, currently, they are
+available on cfg(unix) platforms, Windows, and WASI.
+
+We recommend that new APIs use these types instead of the previous type aliases
+(like [`RawFd`]).
+
+[`RawFd`]: https://doc.rust-lang.org/stable/std/os/unix/io/type.RawFd.html
+[`BorrowedFd`]: https://doc.rust-lang.org/stable/std/os/unix/io/struct.BorrowedFd.html
+
+### Turbofish for generics in functions with `impl Trait`
+
+The turbofish notation (`foo::<u32>()`) can be used to specify the types for explicit type
+parameters (`fn foo<T: Copy>`) even when `impl Trait` is used in the argument types.
+Specifying the type of an `impl Trait` argument via turbofish is still not possible.
+
+### Non-lexical lifetimes migration complete
+
+As detailed in [this blog post], we've fully removed the previous lexical borrow checker
+from rustc across all editions, fully enabling the non-lexical, new, version of the borrow
+checker. Since the borrow checker doesn't affect the output of rustc, this won't change
+the behavior of any programs, but it completes a long-running migration (started in the
+initial stabilization of NLL for the 2018 edition) to deliver the full benefits of the new
+borrow checker across all editions of Rust. For most users, this change will bring
+slightly better diagnostics for some borrow checking errors, but will not otherwise impact
+which code they can write.
+
+You can read more about non-lexical lifetimes in [this section of the 2018 edition announcement][nll].
+
+[this blog post]: https://github.com/rust-lang/blog.rust-lang.org/pull/989
+[nll]: https://blog.rust-lang.org/2018/12/06/Rust-1.31-and-rust-2018.html#non-lexical-lifetimes
+
+### Stabilized APIs
+
+The following methods and trait implementations are now stabilized:
+
+- [`array::from_fn`]
+- [`Box::into_pin`]
+- [`BinaryHeap::try_reserve_exact`]
+- [`BinaryHeap::try_reserve`]
+- [`OsString::try_reserve`]
+- [`OsString::try_reserve_exact`]
+- [`PathBuf::try_reserve`]
+- [`PathBuf::try_reserve_exact`]
+- [`Path::try_exists`]
+- [`Ref::filter_map`]
+- [`RefMut::filter_map`]
+- [`NonNull::<[T]>::len`]
+- [`ToOwned::clone_into`]
+- [`Ipv6Addr::to_ipv4_mapped`]
+- [`unix::io::AsFd`]
+- [`unix::io::BorrowedFd<'fd>`]
+- [`unix::io::OwnedFd`]
+- [`windows::io::AsHandle`]
+- [`windows::io::BorrowedHandle<'handle>`]
+- [`windows::io::OwnedHandle`]
+- [`windows::io::HandleOrInvalid`]
+- [`windows::io::HandleOrNull`]
+- [`windows::io::InvalidHandleError`]
+- [`windows::io::NullHandleError`]
+- [`windows::io::AsSocket`]
+- [`windows::io::BorrowedSocket<'handle>`]
+- [`windows::io::OwnedSocket`]
+- [`thread::scope`]
+- [`thread::Scope`]
+- [`thread::ScopedJoinHandle`]
+
+These APIs are now usable in const contexts:
+
+- [`array::from_ref`]
+- [`slice::from_ref`]
+- [`intrinsics::copy`]
+- [`intrinsics::copy_nonoverlapping`]
+- [`<*const T>::copy_to`]
+- [`<*const T>::copy_to_nonoverlapping`]
+- [`<*mut T>::copy_to`]
+- [`<*mut T>::copy_to_nonoverlapping`]
+- [`<*mut T>::copy_from`]
+- [`<*mut T>::copy_from_nonoverlapping`]
+- [`str::from_utf8`]
+- [`Utf8Error::error_len`]
+- [`Utf8Error::valid_up_to`]
+- [`Condvar::new`]
+- [`Mutex::new`]
+- [`RwLock::new`]
+
+(Links for stabilized APIs are a todo, waiting on release notes to have them.)
+
+### Other changes
+
+There are other changes in the Rust 1.63.0 release. Check out what changed in
+[Rust](https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1630-2022-08-11),
+[Cargo](https://github.com/rust-lang/cargo/blob/master/CHANGELOG.md#cargo-163-2022-08-11),
+and [Clippy](https://github.com/rust-lang/rust-clippy/blob/master/CHANGELOG.md#rust-163).
+
+### Contributors to 1.63.0
+
+Many people came together to create Rust 1.63.0.
+We couldn't have done it without all of you.
+[Thanks!](https://thanks.rust-lang.org/rust/1.63.0/)
+