Rust 1.50.0

Language

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

- [You can now use const values for x in [x; N] array expressions.][79270]

This has been technically possible since 1.38.0, as it was unintentionally stabilized.

- [Assignments to ManuallyDrop union fields are now considered safe.][78068]

Compiler

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

- [Added tier 3\* support for the armv5te-unknown-linux-uclibceabi target.][78142]

- [Added tier 3 support for the aarch64-apple-ios-macabi target.][77484]

- [The x86_64-unknown-freebsd is now built with the full toolset.][79484]

- [Dropped support for all cloudabi targets.][78439]

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

information on Rust's tiered platform support.

Libraries

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

- [proc_macro::Punct now implements PartialEq.][78636]

- [ops::{Index, IndexMut} are now implemented for fixed sized arrays of any length.][74989]

- [On Unix platforms, the std::fs::File type now has a "niche" of -1.][74699]

This value cannot be a valid file descriptor, and now means Option takes

up the same amount of space as File.

Stabilized APIs

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

- [bool::then]

- [btree_map::Entry::or_insert_with_key]

- [f32::clamp]

- [f64::clamp]

- [hash_map::Entry::or_insert_with_key]

- [Ord::clamp]

- [RefCell::take]

- [slice::fill]

- [UnsafeCell::get_mut]

The following previously stable methods are now const.

- [IpAddr::is_ipv4]

- [IpAddr::is_ipv6]

- [IpAddr::is_unspecified]

- [IpAddr::is_loopback]

- [IpAddr::is_multicast]

- [Ipv4Addr::octets]

- [Ipv4Addr::is_loopback]

- [Ipv4Addr::is_private]

- [Ipv4Addr::is_link_local]

- [Ipv4Addr::is_multicast]

- [Ipv4Addr::is_broadcast]

- [Ipv4Addr::is_documentation]

- [Ipv4Addr::to_ipv6_compatible]

- [Ipv4Addr::to_ipv6_mapped]

- [Ipv6Addr::segments]

- [Ipv6Addr::is_unspecified]

- [Ipv6Addr::is_loopback]

- [Ipv6Addr::is_multicast]

- [Ipv6Addr::to_ipv4]

- [Layout::size]

- [Layout::align]

- [Layout::from_size_align]

- pow for all integer types.

- checked_pow for all integer types.

- saturating_pow for all integer types.

- wrapping_pow for all integer types.

- next_power_of_two for all unsigned integer types.

- checked_next_power_of_two for all unsigned integer types.

Cargo

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

- [Added the [build.rustc-workspace-wrapper] option.][cargo/8976]

This option sets a wrapper to execute instead of rustc, for workspace members only.

- [cargo:rerun-if-changed will now, if provided a directory, scan the entire

contents of that directory for changes.][cargo/8973]

- [Added the --workspace flag to the cargo update command.][cargo/8725]

Misc

----

- [The search results tab and the help button are focusable with keyboard in rustdoc.][79896]

- [Running tests will now print the total time taken to execute.][75752]

Compatibility Notes

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

- [The compare_and_swap method on atomics has been deprecated.][79261] It's

recommended to use the compare_exchange and compare_exchange_weak methods instead.

- [Changes in how TokenStreams are checked have fixed some cases where you could write

unhygenic macro_rules! macros.][79472]

- [#![test] as an inner attribute is now considered unstable like other inner macro

attributes, and reports an error by default through the soft_unstable lint.][79003]

- [Overriding a forbid lint at the same level that it was set is now a hard error.][78864]

- [You can no longer intercept panic! calls by supplying your own macro.][78343] It's

recommended to use the #[panic_handler] attribute to provide your own implementation.

- [Semi-colons after item statements (e.g. struct Foo {};) now produce a warning.][78296]

[74989]: https://github.com/rust-lang/rust/pull/74989

[79261]: https://github.com/rust-lang/rust/pull/79261

[79896]: https://github.com/rust-lang/rust/pull/79896

[79484]: https://github.com/rust-lang/rust/pull/79484

[79472]: https://github.com/rust-lang/rust/pull/79472

[79270]: https://github.com/rust-lang/rust/pull/79270

[79003]: https://github.com/rust-lang/rust/pull/79003

[78864]: https://github.com/rust-lang/rust/pull/78864

[78636]: https://github.com/rust-lang/rust/pull/78636

[78439]: https://github.com/rust-lang/rust/pull/78439

[78343]: https://github.com/rust-lang/rust/pull/78343

[78296]: https://github.com/rust-lang/rust/pull/78296

[78068]: https://github.com/rust-lang/rust/pull/78068

[75752]: https://github.com/rust-lang/rust/pull/75752

[74699]: https://github.com/rust-lang/rust/pull/74699

[78142]: https://github.com/rust-lang/rust/pull/78142

[77484]: https://github.com/rust-lang/rust/pull/77484

[cargo/8976]: https://github.com/rust-lang/cargo/pull/8976

[cargo/8973]: https://github.com/rust-lang/cargo/pull/8973

[cargo/8725]: https://github.com/rust-lang/cargo/pull/8725

[IpAddr::is_ipv4]: https://doc.rust-lang.org/stable/std/net/enum.IpAddr.html#method.is_ipv4

[IpAddr::is_ipv6]: https://doc.rust-lang.org/stable/std/net/enum.IpAddr.html#method.is_ipv6

[IpAddr::is_unspecified]: https://doc.rust-lang.org/stable/std/net/enum.IpAddr.html#method.is_unspecified

[IpAddr::is_loopback]: https://doc.rust-lang.org/stable/std/net/enum.IpAddr.html#method.is_loopback

[IpAddr::is_multicast]: https://doc.rust-lang.org/stable/std/net/enum.IpAddr.html#method.is_multicast

[Ipv4Addr::octets]: https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.octets

[Ipv4Addr::is_loopback]: https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.is_loopback

[Ipv4Addr::is_private]: https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.is_private

[Ipv4Addr::is_link_local]: https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.is_link_local

[Ipv4Addr::is_multicast]: https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.is_multicast

[Ipv4Addr::is_broadcast]: https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.is_broadcast

[Ipv4Addr::is_documentation]: https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.is_documentation

[Ipv4Addr::to_ipv6_compatible]: https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.to_ipv6_compatible

[Ipv4Addr::to_ipv6_mapped]: https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.to_ipv6_mapped

[Ipv6Addr::segments]: https://doc.rust-lang.org/stable/std/net/struct.Ipv6Addr.html#method.segments

[Ipv6Addr::is_unspecified]: https://doc.rust-lang.org/stable/std/net/struct.Ipv6Addr.html#method.is_unspecified

[Ipv6Addr::is_loopback]: https://doc.rust-lang.org/stable/std/net/struct.Ipv6Addr.html#method.is_loopback

[Ipv6Addr::is_multicast]: https://doc.rust-lang.org/stable/std/net/struct.Ipv6Addr.html#method.is_multicast

[Ipv6Addr::to_ipv4]: https://doc.rust-lang.org/stable/std/net/struct.Ipv6Addr.html#method.to_ipv4

[Layout::align]: https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.align

[Layout::from_size_align]: https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.from_size_align

[Layout::size]: https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.size

[Ord::clamp]: https://doc.rust-lang.org/stable/std/cmp/trait.Ord.html#method.clamp

[RefCell::take]: https://doc.rust-lang.org/stable/std/cell/struct.RefCell.html#method.take

[UnsafeCell::get_mut]: https://doc.rust-lang.org/stable/std/cell/struct.UnsafeCell.html#method.get_mut

[bool::then]: https://doc.rust-lang.org/stable/std/primitive.bool.html#method.then

[btree_map::Entry::or_insert_with_key]: https://doc.rust-lang.org/stable/std/collections/btree_map/enum.Entry.html#method.or_insert_with_key

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

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

[hash_map::Entry::or_insert_with_key]: https://doc.rust-lang.org/stable/std/collections/hash_map/enum.Entry.html#method.or_insert_with_key

[slice::fill]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.fill