Rust 1.24.0

Language

--------

- [External sysv64 ffi is now available.][46528]

eg. extern "sysv64" fn foo () {}

Compiler

--------

- [rustc now uses 16 codegen units by default for release builds.][46910]

For the fastest builds, utilize codegen-units=1.

- [Added armv4t-unknown-linux-gnueabi target.][47018]

- [Add aarch64-unknown-openbsd support][46760]

Libraries

---------

- [str::find:: now uses memchr.][46735] This should lead to a 10x

improvement in performance in the majority of cases.

- [OsStr's Debug implementation is now lossless and consistent

with Windows.][46798]

- [time::{SystemTime, Instant} now implement Hash.][46828]

- [impl From for AtomicBool][46293]

- [impl From<{CString, &CStr}> for {Arc, Rc}][45990]

- [impl From<{OsString, &OsStr}> for {Arc, Rc}][45990]

- [impl From<{PathBuf, &Path}> for {Arc, Rc}][45990]

- [float::from_bits now just uses transmute.][46012] This provides

some optimisations from LLVM.

- [Copied AsciiExt methods onto char][46077]

- [Remove T: Sized requirement on ptr::is_null()][46094]

- [impl From for {TryRecvError, RecvTimeoutError}][45506]

- [Optimised f32::{min, max} to generate more efficient x86 assembly][47080]

- [[u8]::contains now uses memchr which provides a 3x speed improvement][46713]

Stabilized APIs

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

- [RefCell::replace]

- [RefCell::swap]

- [atomic::spin_loop_hint]

The following functions can now be used in a constant expression.

eg. let buffer: [u8; size_of::()];, static COUNTER: AtomicUsize = AtomicUsize::new(1);

- [AtomicBool::new][46287]

- [AtomicUsize::new][46287]

- [AtomicIsize::new][46287]

- [AtomicPtr::new][46287]

- [Cell::new][46287]

- [{integer}::min_value][46287]

- [{integer}::max_value][46287]

- [mem::size_of][46287]

- [mem::align_of][46287]

- [ptr::null][46287]

- [ptr::null_mut][46287]

- [RefCell::new][46287]

- [UnsafeCell::new][46287]

Cargo

-----

- [Added a workspace.default-members config that

overrides implied --all in virtual workspaces.][cargo/4743]

- [Enable incremental by default on development builds.][cargo/4817] Also added

configuration keys to Cargo.toml and .cargo/config to disable on a

per-project or global basis respectively.

Misc

----

Compatibility Notes

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

- [Floating point types Debug impl now always prints a decimal point.][46831]

- [Ipv6Addr now rejects superfluous ::'s in IPv6 addresses][46671] This is

in accordance with IETF RFC 4291 §2.2.

- [Unwinding will no longer go past FFI boundaries, and will instead abort.][46833]

- [Formatter::flags method is now deprecated.][46284] The sign_plus,

sign_minus, alternate, and sign_aware_zero_pad should be used instead.

- [Leading zeros in tuple struct members is now an error][47084]

- [column!() macro is one-based instead of zero-based][46977]

- [fmt::Arguments can no longer be shared across threads][45198]

- [Access to #[repr(packed)] struct fields is now unsafe][44884]

- [Cargo sets a different working directory for the compiler][cargo/4788]

[44884]: https://github.com/rust-lang/rust/pull/44884

[45198]: https://github.com/rust-lang/rust/pull/45198

[45506]: https://github.com/rust-lang/rust/pull/45506

[45990]: https://github.com/rust-lang/rust/pull/45990

[46012]: https://github.com/rust-lang/rust/pull/46012

[46077]: https://github.com/rust-lang/rust/pull/46077

[46094]: https://github.com/rust-lang/rust/pull/46094

[46284]: https://github.com/rust-lang/rust/pull/46284

[46287]: https://github.com/rust-lang/rust/pull/46287

[46293]: https://github.com/rust-lang/rust/pull/46293

[46528]: https://github.com/rust-lang/rust/pull/46528

[46671]: https://github.com/rust-lang/rust/pull/46671

[46713]: https://github.com/rust-lang/rust/pull/46713

[46735]: https://github.com/rust-lang/rust/pull/46735

[46760]: https://github.com/rust-lang/rust/pull/46760

[46798]: https://github.com/rust-lang/rust/pull/46798

[46828]: https://github.com/rust-lang/rust/pull/46828

[46831]: https://github.com/rust-lang/rust/pull/46831

[46833]: https://github.com/rust-lang/rust/pull/46833

[46910]: https://github.com/rust-lang/rust/pull/46910

[46977]: https://github.com/rust-lang/rust/pull/46977

[47018]: https://github.com/rust-lang/rust/pull/47018

[47080]: https://github.com/rust-lang/rust/pull/47080

[47084]: https://github.com/rust-lang/rust/pull/47084

[cargo/4743]: https://github.com/rust-lang/cargo/pull/4743

[cargo/4788]: https://github.com/rust-lang/cargo/pull/4788

[cargo/4817]: https://github.com/rust-lang/cargo/pull/4817

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

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

[atomic::spin_loop_hint]: https://doc.rust-lang.org/std/sync/atomic/fn.spin_loop_hint.html