Rust is a general-purpose programming language which emphasizes performance, type safety, concurrency, and memory safety.
Update Jul 16, 2026 tracked by Updatify
Update Jul 9, 2026 tracked by Updatify
Result<T, Uninhabited> and ControlFlow<Uninhabited, T> to be equivalent to T for must use lint dead_code_pub_in_binary lint for unused pub items in binary crates div32, lam-bh, lamcas, ld-seq-sa and scq target features cfg(target_has_atomic_primitive_alignment) self in imports in more cases Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
Default for RepeatN Copy for ffi::FromBytesUntilNulError Send for std::fs::File on UEFI <{integer}>::isolate_highest_one <{integer}>::isolate_lowest_one <{integer}>::highest_one <{integer}>::lowest_one <{integer}>::bit_width NonZero<{integer}>::isolate_highest_one NonZero<{integer}>::isolate_lowest_one NonZero<{integer}>::highest_one NonZero<{integer}>::lowest_one NonZero<{integer}>::bit_width These previously stable APIs are now stable in const contexts:
build.warnings config. This controls how lint warnings from local packages are treated. Useful for enforcing a warning-free build in CI, replacing -Dwarnings. docs resolver.lockfile-path config. This allows specifying the path to the lockfile to use when resolving dependencies. Useful when working with read-only source directories. docs --target-dir doesn’t look like a Cargo target directory. This prevents accidental deletion of non-target directories. -m shorthand for --manifest-path curl dependency from crates-io crate f32: From<{float}> to constrain {float} pin!, in order to prevent unsoundness. The most likely case where this might impact users is: writing pin!(x) where x has type &mut T will now always correctly produce a value of type Pin<&mut &mut T>, instead of sometimes allowing a coercion that produces a value of type Pin<&mut T>. This coercion was previously incorrectly allowed since Rust 1.88.0. std::char constants and functions f64 methods which have been deprecated since 1.0 varargs_without_pattern lint in deps link_section specifier enums have changed. This is not a breaking change, as it only applies to enums without layout guarantees, but is noted here as we’ve seen people impacted from having made assumptions about the layout algorithm. #[export_name = "..."] where the name is empty #[link_name = "..."] & #[link(name = "...")] parameters shutdown on a socket to shut down the write side, attempting to write to the socket will now produce a BrokenPipe error rather than Other. Map WSAESHUTDOWN to io::ErrorKind::BrokenPipe Update May 28, 2026 tracked by Updatify
expr metavariable to cfg ManuallyDrop as patterns (fixing a regression introduced in 1.94.0) riscv64gc-unknown-fuchsia baseline to RVA22 + vector NonZero integers assert_matches! debug_assert_matches! From<T> for AssertUnwindSafe<T> From<T> for LazyCell<T, F> From<T> for LazyLock<T, F> core::range::RangeToInclusive core::range::RangeToInclusiveIter core::range::RangeFrom core::range::RangeFromIter core::range::Range core::range::RangeIter target.'cfg(..)'.rustdocflags support in configuration. white-space: pre-wrap; property and stripped any <p> elements from the rendered html, however this caused issues and unintuitive behavior. The new behavior should be more predictable, however some multi-line deprecation notes will now be rendered as as single lines. If this is undesirable, you can use the standard markdown method of forcing a linebreak, which is two spaces followed by a newline ("\n"). missing_doc_code_examples lint on impl items #[repr(Int)] enums in some edge cases involving fields of uninhabited zero-sized types Pin<Foo> where Foo doesn’t implement Deref. Some such coercions were previously allowed, but produce a type with no useful public API. --allow-undefined on wasm targets #![reexport_test_harness_main] attribute uninhabited_static lint in dependencies and make it deny-by-default -Csoft-float ::{self [as name]}, e.g., struct S {}; use S::{self as Other};, is now no longer permitted because {self} imports require a module parent. export_name, link_name, and link_section attributes, if multiple of the same attribute is present, the first one now takes precedence. avr targets, C’s double type is 32-bit by default, so change c_double to f32 on avr targets to match. This is a breaking change, but necessary to make c_double match C’s double. BTreeMap::append() was optimized, which may now cause panics for types with incorrect Ord impls These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Apr 16, 2026 tracked by Updatify
if let guards on match arms irrefutable_let_patterns lint no longer lints on let chains --remap-path-scope for controlling the scoping of how paths get remapped in the resulting binary powerpc64-unknown-linux-musl to Tier 2 with host tools aarch64-apple-tvos to Tier 2 aarch64-apple-tvos-sim to Tier 2 aarch64-apple-watchos to Tier 2 aarch64-apple-watchos-sim to Tier 2 aarch64-apple-visionos to Tier 2 aarch64-apple-visionos-sim to Tier 2 Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
thread::scope: document how join interacts with TLS destructors str::contains on aarch64 targets with neon target feature enabled by default MaybeUninit<[T; N]>: From<[MaybeUninit<T>; N]> MaybeUninit<[T; N]>: AsRef<[MaybeUninit<T>; N]> MaybeUninit<[T; N]>: AsRef<[MaybeUninit<T>]> MaybeUninit<[T; N]>: AsMut<[MaybeUninit<T>; N]> MaybeUninit<[T; N]>: AsMut<[MaybeUninit<T>]> [MaybeUninit<T>; N]: From<MaybeUninit<[T; N]>> Cell<[T; N]>: AsRef<[Cell<T>; N]> Cell<[T; N]>: AsRef<[Cell<T>]> Cell<[T]>: AsRef<[Cell<T>]> bool: TryFrom<{integer}> AtomicPtr::update AtomicPtr::try_update AtomicBool::update AtomicBool::try_update AtomicIn::update AtomicIn::try_update AtomicUn::update AtomicUn::try_update cfg_select! mod core::range core::range::RangeInclusive core::range::RangeInclusiveIter core::hint::cold_path <*const T>::as_ref_unchecked <*mut T>::as_ref_unchecked <*mut T>::as_mut_unchecked Vec::push_mut Vec::insert_mut VecDeque::push_front_mut VecDeque::push_back_mut VecDeque::insert_mut LinkedList::push_front_mut LinkedList::push_back_mut Layout::dangling_ptr Layout::repeat Layout::repeat_packed Layout::extend_packed These previously stable APIs are now stable in const contexts:
$crate without renaming, i.e. use $crate::{self};, is now no longer permitted due to stricter error checking for self imports. const or static. ambiguous_glob_imported_traits is now reported when using an ambiguously glob imported trait Eq::assert_receiver_is_total_eq and emit future compatibility warnings on manual impls #[non_exhaustive] enum now reads the discriminant, even if the enum has only one variant. This can cause closures to capture values that they previously wouldn’t. mut ref and mut ref mut patterns, part of the unstable Match Ergonomics 2024 RFC, were accidentally allowed on stable within struct pattern field shorthand. These patterns are now correctly feature-gated as unstable in this position. -Z unstable-options to use. Previously, they could not be used without the standard library, which has no stable build mechanism. In preparation for the build-std project adding that support, JSON target specs are being proactively gated to ensure they remain unstable even if build-std is stabilized. Cargo now includes the -Z json-target-spec CLI flag to automatically pass -Z unstable-options to the compiler when needed. See #150151, #151534, and rust-lang/cargo#16557. #[feature] attributes on invalid targets are now checked These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Mar 26, 2026 tracked by Updatify
std::thread::spawn on wasm32-wasip1-threads std::os::windows::fs::OpenOptionsExt The new methods were unstable, but the trait itself is not sealed and so cannot be extended with non-default methods. match_same_arms Update Mar 5, 2026 tracked by Updatify
dead_code lint level of the corresponding traits and trait items unused_visibilities lint for visibility on const _ declarations Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
<[T]>::array_windows <[T]>::element_offset LazyCell::get LazyCell::get_mut LazyCell::force_mut LazyLock::get LazyLock::get_mut LazyLock::force_mut impl TryFrom<char> for usize std::iter::Peekable::next_if_map std::iter::Peekable::next_if_map_mut avx512fp16 intrinsics (excluding those that depend directly on the unstable f16 type) f16 type) f32::consts::EULER_GAMMA f64::consts::EULER_GAMMA f32::consts::GOLDEN_RATIO f64::consts::GOLDEN_RATIO These previously stable APIs are now stable in const contexts:
CARGO_BIN_EXE_<crate> available at runtime dyn-types Drop to run at a different point in time. #[macro_use] This will raise an error if macros of the same name are glob imported. For example if a crate defines their own matches macro and then glob imports that, it’s now ambiguous whether the custom or standard library matches is meant and an explicit import of the name is required to resolve the ambiguity. One exception is core::panic and std::panic, if their import is ambiguous a new warning (ambiguous_panic_imports) is raised. This may raise a new warning (ambiguous_panic_imports) on #![no_std] code glob importing the std crate. Both core::panic! and std::panic! are then in scope and which is used is ambiguous. include!(…)s This can cause previously working includes to no longer compile if they included files which started with a shebang. std::time::SystemTime::checked_sub_duration will return None for times before the Windows epoch (1/1/1601) 'a are now NFC normalized. --remap-path-prefix given originally. One side-effect of this change is that paths emitted for local crates in Cargo (path dependencies and workspace members) are no longer absolute but relative when emitted as part of a diagnostic in a downstream crate. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
annotate-snippets for error emission This should preserve mostly the same outputs in rustc error messages. Update Feb 12, 2026 tracked by Updatify
clippy::panicking_unwrap false-positive on field access with implicit deref. wasm32-wasip2 target. Update Jan 22, 2026 tracked by Updatify
vector-related target features and the is_s390x_feature_detected! macro system ABI cfg predicate asm_cfg const items that contain mutable references to static (which is very unsafe, but not always UB) const_item_interior_mutations lint to warn against calls which mutate interior mutable const items function_casts_as_integer lint -Cjump-tables=bool. The flag was previously called -Zno-jump-tables. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
specialization on the Copy trait as it is unsound in the presence of lifetime dependent Copy implementations. This may result in some performance regressions as some standard library APIs may now call Clone::clone instead of performing bitwise copies std::thread::current() BTree::append not update existing keys when appending an entry which already exists T: RefUnwindSafe for vec::IntoIter<T>: UnwindSafe <[MaybeUninit<T>]>::assume_init_drop <[MaybeUninit<T>]>::assume_init_ref <[MaybeUninit<T>]>::assume_init_mut <[MaybeUninit<T>]>::write_copy_of_slice <[MaybeUninit<T>]>::write_clone_of_slice String::into_raw_parts Vec::into_raw_parts <iN>::unchecked_neg <iN>::unchecked_shl <iN>::unchecked_shr <uN>::unchecked_shl <uN>::unchecked_shr <[T]>::as_array <[T]>::as_mut_array <*const [T]>::as_array <*mut [T]>::as_mut_array VecDeque::pop_front_if VecDeque::pop_back_if Duration::from_nanos_u128 char::MAX_LEN_UTF8 char::MAX_LEN_UTF16 std::fmt::from_fn std::fmt::FromFn cargo tree, support long forms for --format variables --workspace to cargo clean #![doc(document_private_items)] import html_favicon_url, html_logo_url, html_playground_url, issue_tracker_base_url, or html_no_source either has a missing value, an unexpected value, or a value of the wrong type, rustdoc will emit the deny-by-default lint rustdoc::invalid_doc_attributes. pin_v2 into the builtin attributes namespace panic=unwind was changed from the JS exception handling ABI to the wasm exception handling ABI. If linking C/C++ object files with Rust objects, -fwasm-exceptions must be passed to the linker now. On nightly Rust, it is possible to get the old behavior with -Zwasm-emscripten-eh=false -Zbuild-std, but it will be removed in a future release. #[test] attribute, used to define tests, was previously ignored in various places where it had no meaning (e.g on trait methods or types). Putting the #[test] attribute in these places is no longer ignored, and will now result in an error; this may also result in errors when generating rustdoc. Error when test attribute is applied to structs CARGO_CFG_DEBUG_ASSERTIONS environment variable in more situations. This will cause crates depending on static-init versions 1.0.1 to 1.0.3 to fail compilation with “failed to resolve: use of unresolved module or unlinked crate parking_lot“. See the linked issue for details. offset_of! macro are now checked to be well formed. cargo publish no longer emits .crate files as a final artifact for user access when the build.build-dir config is unset deref_nullptr lint from warn-by-default to deny-by-default ... function parameters without a pattern outside of extern blocks repr(C) enums whose discriminant values do not fit into a c_int or c_uint repr(C) types as part of repr(transparent) Update Dec 11, 2025 tracked by Updatify
MaybeUninit representation and validity Sized X in [X; 0] when X is unsizing a const #[track_caller] and #[no_mangle] (requires every declaration specifying #[track_caller] as well) never_type_fallback_flowing_into_unsafe and dependency_on_unit_never_type_fallback deny-by-default unused_must_use lint no longer warns on Result<(), Uninhabited> (for instance, Result<(), !>), or ControlFlow<Uninhabited, ()>. This avoids having to check for an error that can never happen. mips64el-unknown-linux-muslabi64 link dynamically Iterator::eq{_by} for TrustedLen iterators Extend for tuples Debug for EncodeWide. iter::Repeat::last and count will now panic, rather than looping infinitely. NonZero<u{N}>::div_ceil Location::file_as_c_str RwLockWriteGuard::downgrade Box::new_zeroed Box::new_zeroed_slice Rc::new_zeroed Rc::new_zeroed_slice Arc::new_zeroed Arc::new_zeroed_slice btree_map::Entry::insert_entry btree_map::VacantEntry::insert_entry impl Extend<proc_macro::Group> for proc_macro::TokenStream impl Extend<proc_macro::Literal> for proc_macro::TokenStream impl Extend<proc_macro::Punct> for proc_macro::TokenStream impl Extend<proc_macro::Ident> for proc_macro::TokenStream These previously stable APIs are now stable in const contexts:
Iterator::last as well as impl methods like std::vec::IntoIter::last. Now these impl methods will be hidden, freeing up space for inherent methods like BTreeSet::last. -C panic=abort on Linux by generating unwind tables by default. Build with -C force-unwind-tables=no to keep omitting unwind tables. invalid_macro_export_arguments is upgraded to deny-by-default and will be reported in dependencies too. impl DerefMut for Pin<LocalType> pin! and formatting macros Update Nov 10, 2025 tracked by Updatify
wasm_import_module attribute cross-crate. This fixes linker errors on WASM targets. Update Oct 30, 2025 tracked by Updatify
sysv64, win64, efiapi, and aapcs ABIs. This brings these ABIs in line with the C ABI: variadic functions can be declared in extern blocks but not defined. dangling_pointers_from_locals lint to warn against dangling pointers from local variables semicolon_in_expressions_from_macros from warn to deny integer_to_ptr_transmutes lint against integer-to-pointer transmutes sse4a and tbm target features target_env = "macabi" and target_env = "sim" cfgs as replacements for the target_abi cfgs with the same values. aarch64-pc-windows-gnullvm and x86_64-pc-windows-gnullvm to Tier 2 with host tools. Note: llvm-tools and MSI installers are missing but will be added in future releases. aarch64-pc-windows-msvc to Tier 1 Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
core::panic::Location::file return type _by() variants of min / max/ minmax in std::cmp Clone and Eq traits std::thread: Return error if setting thread stack size fails This used to panic within the standard library. Path::file_prefix AtomicPtr::fetch_ptr_add AtomicPtr::fetch_ptr_sub AtomicPtr::fetch_byte_add AtomicPtr::fetch_byte_sub AtomicPtr::fetch_or AtomicPtr::fetch_and AtomicPtr::fetch_xor {integer}::strict_add {integer}::strict_sub {integer}::strict_mul {integer}::strict_div {integer}::strict_div_euclid {integer}::strict_rem {integer}::strict_rem_euclid {integer}::strict_neg {integer}::strict_shl {integer}::strict_shr {integer}::strict_pow i{N}::strict_add_unsigned i{N}::strict_sub_unsigned i{N}::strict_abs u{N}::strict_add_signed u{N}::strict_sub_signed PanicHookInfo::payload_as_str core::iter::chain u{N}::checked_signed_diff core::array::repeat PathBuf::add_extension PathBuf::with_added_extension Duration::from_mins Duration::from_hours impl PartialEq<str> for PathBuf impl PartialEq<String> for PathBuf impl PartialEq<str> for Path impl PartialEq<String> for Path impl PartialEq<PathBuf> for String impl PartialEq<Path> for String impl PartialEq<PathBuf> for str impl PartialEq<Path> for str Ipv4Addr::from_octets Ipv6Addr::from_octets Ipv6Addr::from_segments impl<T> Default for Pin<Box<T>> where Box<T>: Default, T: ?Sized impl<T> Default for Pin<Rc<T>> where Rc<T>: Default, T: ?Sized impl<T> Default for Pin<Arc<T>> where Arc<T>: Default, T: ?Sized Cell::as_array_of_cells u{N}::carrying_add u{N}::borrowing_sub u{N}::carrying_mul u{N}::carrying_mul_add BTreeMap::extract_if BTreeSet::extract_if impl Debug for windows::ffi::EncodeWide<'_> str::ceil_char_boundary str::floor_char_boundary impl Sum for Saturating<u{N}> impl Sum<&Self> for Saturating<u{N}> impl Product for Saturating<u{N}> impl Product<&Self> for Saturating<u{N}> These previously stable APIs are now stable in const contexts:
<[T; N]>::each_ref <[T; N]>::each_mut OsString::new PathBuf::new TypeId::of ptr::with_exposed_provenance ptr::with_exposed_provenance_mut build.build-dir. This config sets the directory where intermediate build artifacts are stored. These artifacts are produced by Cargo and rustc during the build process. End users usually won’t need to interact with them, and the layout inside build-dir is an implementation detail that may change without notice. (config doc) (build cache doc) #15833 #15840 --target flag and the build.target configuration can now take literal "host-tuple" string, which will internally be substituted by the host machine’s target triple. #15838 #16003 #16032 *const u8 ->, and additionally functions that take or return raw pointers will now display their signature properly in search results. cc, and pass it via SDKROOT env var. This should fix linking issues with rustc running inside Xcode. Libraries in /usr/local/lib may no longer be linked automatically, if you develop or use a crate that relies on this, you should explicitly set cargo::rustc-link-search=/usr/local/lib in a build.rs script. TraitRef<AssocTy: ?Sized> are now correctly forbidden #[sanitize(xyz = "on|off")] built-in attribute that shadows procedural macros with the same name semicolon_in_expressions_from_macros, for macro_rules! macros in expression position that expand to end in a semicolon (;), is now deny-by-default. It was already warn-by-default, and a future compatibility warning (FCW) that warned even in dependencies. This lint will become a hard error in the future. unsafe, !, default) in inherent impls are no longer syntactically valid ill_formed_attribute_input in dependencies pin!, format_args!, write!, and writeln! in if let scrutinees in Rust Edition 2024. This applies Rust Edition 2024’s if let temporary scope rules to these temporaries, which previously could live past the if expression regardless of Edition. static are now syntactically invalid --cfg and --check-cfg arguments are no longer allowed Cargo compatibility notes:
cargo publish no longer keeps .crate tarballs as final build artifacts when build.build-dir is set. These tarballs were previously included due to an oversight and are now treated as intermediate artifacts. To get .crate tarballs as final artifacts, use cargo package. In a future version, this change will apply regardless of build.build-dir. #15910 build-dir may not work for users changing their build-dir layout. For those doing so, we’d recommend proactively testing these cases particularly as we are considering changing the default location of the build-dir in the future (cargo#16147). If you can’t migrate off of Cargo’s internal details, we’d like to learn more about your use case as we prepare to change the layout of the build-dir (cargo#15010). These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Sep 18, 2025 tracked by Updatify
unknown_or_malformed_diagnostic_attributes lint. This lint has been split up into four finer-grained lints, with unknown_or_malformed_diagnostic_attributes now being the lint group that contains these lints: unknown_diagnostic_attributes: unknown to the current compiler misplaced_diagnostic_attributes: placed on the wrong item malformed_diagnostic_attributes: malformed attribute syntax or options malformed_diagnostic_format_literals: malformed format string literal lld by default on x86_64-unknown-linux-gnu. musl targets now link dynamically by default. Affected targets: mips64-unknown-linux-muslabi64 powerpc64-unknown-linux-musl powerpc-unknown-linux-musl powerpc-unknown-linux-muslspe riscv32gc-unknown-linux-musl s390x-unknown-linux-musl thumbv7neon-unknown-linux-musleabihf Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
u*::{checked,overflowing,saturating,wrapping}_sub_signed CStr, CString, and Cow<CStr> MSG_NOSIGNAL for UnixStream proc_macro::Ident::new now supports $crate. Thread::into_raw has at least 8 bytes of alignment u{n}::checked_sub_signed u{n}::overflowing_sub_signed u{n}::saturating_sub_signed u{n}::wrapping_sub_signed impl Copy for IntErrorKind impl Hash for IntErrorKind impl PartialEq<&CStr> for CStr impl PartialEq<CString> for CStr impl PartialEq<Cow<CStr>> for CStr impl PartialEq<&CStr> for CString impl PartialEq<CStr> for CString impl PartialEq<Cow<CStr>> for CString impl PartialEq<&CStr> for Cow<CStr> impl PartialEq<CStr> for Cow<CStr> impl PartialEq<CString> for Cow<CStr> These previously stable APIs are now stable in const contexts:
<[T]>::reverse f32::floor f32::ceil f32::trunc f32::fract f32::round f32::round_ties_even f64::floor f64::ceil f64::trunc f64::fract f64::round f64::round_ties_even http.proxy-cainfo config for proxy certs gix for cargo package impl blocks, now they do when shift is held unsafe() wrappers lld by default on x86_64-unknown-linux-gnu. See also https://blog.rust-lang.org/2025/09/01/rust-lld-on-1.90.0-stable/. core::iter::Fuse‘s Default impl construct I::default() internally as promised in the docs instead of always being empty MSG_NOSIGNAL for UnixStream This may change program behavior but results in the same behavior as other primitives (e.g., stdout, network sockets). Programs relying on signals to terminate them should update handling of sockets to handle errors on write by exiting. std::env::home_dir will use the fallback if the HOME environment variable is empty extern "{abi}"s consistently in all positions. This primarily affects the use of implementing traits on an extern "{abi}" function pointer, like extern "stdcall" fn(), on a platform that doesn’t support that, like aarch64-unknown-linux-gnu. Direct usage of these unsupported ABI strings by declaring or defining functions was already rejected, so this is only a change for consistency. proc_macro_derive macro has correct arguments when applied to the crate root Update Aug 7, 2025 tracked by Updatify
feature(generic_arg_infer)) mismatched_lifetime_syntaxes lint. This lint detects when the same lifetime is referred to by different syntax categories between function arguments and return values, which can be confusing to read, especially in unsafe code. This lint supersedes the warn-by-default elided_named_lifetimes lint. unpredictable_function_pointer_comparisons to also lint on function pointer comparisons in external macros dangerous_implicit_autorefs lint deny-by-default kl and widekl target features for x86 sha512, sm3 and sm4 target features for x86 f, d, frecipe, lasx, lbt, lsx, and lvz i128 and u128 from improper_ctypes_definitions repr128 (#[repr(u128)], #[repr(i128)]) #![doc(test(attr(..)))] everywhere extern "C" functions on the wasm32-unknown-unknown target now have a standards compliant ABI loongarch32-unknown-none and loongarch32-unknown-none-softfloat x86_64-apple-darwin is in the process of being demoted to Tier 2 with host tools Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
file! format_args!() in a variable #[must_use] to [T; N]::map DerefMut for Lazy{Cell,Lock} Default for array::IntoIter Clone for slice::ChunkBy io::Seek for io::Take NonZero<char> File::lock File::lock_shared File::try_lock File::try_lock_shared File::unlock NonNull::from_ref NonNull::from_mut NonNull::without_provenance NonNull::with_exposed_provenance NonNull::expose_provenance OsString::leak PathBuf::leak Result::flatten std::os::linux::net::TcpStreamExt::quickack std::os::linux::net::TcpStreamExt::set_quickack These previously stable APIs are now stable in const contexts:
cargo fix and cargo clippy --fix now default to the same Cargo target selection as other build commands. Previously it would apply to all targets (like binaries, examples, tests, etc.). The --edition flag still applies to all targets. runner setting to run the tests. If you need to disable tests for a target, you can use the ignore doctest attribute to specify the targets to ignore. missing_fragment_specifier an unconditional error neon target feature on aarch64-unknown-none-softfloat causes a warning because mixing code with and without that target feature is not properly supported by LLVM ?Sized bounds on impls on recursive types which contain associated type projections. It is not expected to affect any existing published crates. Can be fixed by refactoring the involved types or opting into the sized_hierarchy unstable feature. See the FCP report for a code example. elided_named_lifetimes lint is superseded by the warn-by-default mismatched_lifetime_syntaxes lint. Copy are now only available at the end of type checking std::intrinsics::{copy,copy_nonoverlapping,write_bytes} are now proper intrinsics. There are no debug assertions guarding against UB, and they cannot be coerced to function pointers. std::intrinsics::drop_in_place !) are now reported in dependencies std::ptr::copy_* intrinsics also perform the static self-init checks extern "C" functions on the wasm32-unknown-unknown target now have a standards compliant ABI These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Jun 26, 2025 tracked by Updatify
#![feature(let_chains)] in the 2024 edition. This feature allows &&-chaining let statements inside if and while, allowing intermixture with boolean expressions. The patterns inside the let sub-expressions can be irrefutable or refutable. #![feature(naked_functions)]. Naked functions allow writing functions with no compiler-generated epilogue and prologue, allowing full control over the generated assembly for a particular function. #![feature(cfg_boolean_literals)]. This allows using boolean literals as cfg predicates, e.g. #[cfg(true)] and #[cfg(false)]. #[bench] attribute. Usage of #[bench] without #![feature(custom_test_frameworks)] already triggered a deny-by-default future-incompatibility lint since Rust 1.77, but will now become a hard error. dangerous_implicit_autorefs lint against implicit autoref of raw pointer dereference. The lint will be bumped to deny-by-default in the next version of Rust. invalid_null_arguments lint to prevent invalid usage of null pointers. This lint is uplifted from clippy::invalid_null_ptr_usage. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
#[should_panic] test failure message. [T; N]::from_fn is generated in order of increasing indices., for those passing it a stateful closure. --nocapture is deprecated in favor of the more consistent --no-capture flag. {float}::NAN is a quiet NaN. Cell::update impl Default for *const T impl Default for *mut T HashMap::extract_if HashSet::extract_if hint::select_unpredictable proc_macro::Span::line proc_macro::Span::column proc_macro::Span::start proc_macro::Span::end proc_macro::Span::file proc_macro::Span::local_file <[T]>::as_chunks <[T]>::as_chunks_mut <[T]>::as_chunks_unchecked <[T]>::as_chunks_unchecked_mut <[T]>::as_rchunks <[T]>::as_rchunks_mut mod ffi::c_str These previously stable APIs are now stable in const contexts:
NonNull<T>::replace <*mut T>::replace std::ptr::swap_nonoverlapping Cell::replace Cell::get Cell::get_mut Cell::from_mut Cell::as_slice_of_cells ignore-* attributes. --test-runtool and --test-runtool-arg CLI options to specify a program (like qemu) and its arguments to run a doctest. tt fragment specifier can often fix these macros. #[bench] attribute. Usage of #[bench] without #![feature(custom_test_frameworks)] already triggered a deny-by-default future-incompatibility lint since Rust 1.77, but will now become a hard error. Update May 15, 2025 tracked by Updatify
asm_goto feature ..EXPR) after unary operators !, -, and *. Self: Sized bounds in impls for unsized types feature(precise_capturing_in_traits) allowing use<...> bounds on return position impl Trait in traits Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
Debug impl of raw pointers Vec::with_capacity guarantees it allocates with the amount requested, even if Vec::capacity returns a different number. std::arch intrinsics which don’t take pointer arguments can now be called from safe code if the caller has the appropriate target features already enabled (https://github.com/rust-lang/stdarch/pull/1714, https://github.com/rust-lang/stdarch/pull/1716, https://github.com/rust-lang/stdarch/pull/1717) env::home_dir ControlFlow as #[must_use] assert_eq! and vec! now support const {...} expressions Vec::extract_if vec::ExtractIf LinkedList::extract_if linked_list::ExtractIf <[T]>::split_off <[T]>::split_off_mut <[T]>::split_off_first <[T]>::split_off_first_mut <[T]>::split_off_last <[T]>::split_off_last_mut String::extend_from_within os_str::Display OsString::display OsStr::display io::pipe io::PipeReader io::PipeWriter impl From<PipeReader> for OwnedHandle impl From<PipeWriter> for OwnedHandle impl From<PipeReader> for Stdio impl From<PipeWriter> for Stdio impl From<PipeReader> for OwnedFd impl From<PipeWriter> for OwnedFd Box<MaybeUninit<T>>::write impl TryFrom<Vec<u8>> for String <*const T>::offset_from_unsigned <*const T>::byte_offset_from_unsigned <*mut T>::offset_from_unsigned <*mut T>::byte_offset_from_unsigned NonNull::offset_from_unsigned NonNull::byte_offset_from_unsigned <uN>::cast_signed NonZero::<uN>::cast_signed. <iN>::cast_unsigned. NonZero::<iN>::cast_unsigned. <uN>::is_multiple_of <uN>::unbounded_shl <uN>::unbounded_shr <iN>::unbounded_shl <iN>::unbounded_shr <iN>::midpoint <str>::from_utf8 <str>::from_utf8_mut <str>::from_utf8_unchecked <str>::from_utf8_unchecked_mut These previously stable APIs are now stable in const contexts:
core::str::from_utf8_mut <[T]>::copy_from_slice SocketAddr::set_ip SocketAddr::set_port, SocketAddrV4::set_ip SocketAddrV4::set_port, SocketAddrV6::set_ip SocketAddrV6::set_port SocketAddrV6::set_flowinfo SocketAddrV6::set_scope_id char::is_digit char::is_whitespace <[[T; N]]>::as_flattened <[[T; N]]>::as_flattened_mut String::into_bytes String::as_str String::capacity String::as_bytes String::len String::is_empty String::as_mut_str String::as_mut_vec Vec::as_ptr Vec::as_slice Vec::capacity Vec::len Vec::is_empty Vec::as_mut_slice Vec::as_mut_ptr #![crate_name] attribute Debug impl of raw pointers print metadata if present dyn types are no longer deduplicated .. inside of struct patterns (let Struct { #[attribute] .. }) = ptr_cast_add_auto_to_object lint into hard error std::arch intrinsics are now safe to call in some contexts, there may now be new unused_unsafe warnings in existing codebases. width and precision formatting options to 16 bits on all targets ControlFlow as #[must_use] advapi32, except on win7. Code such as C libraries that were relying on this assumption may need to explicitly link advapi32. cfg(true) attributes. tt fragment specifier can often fix these macros. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Apr 3, 2025 tracked by Updatify
#[target_feature] attribute. missing_abi lint now warns-by-default. --x) as written in other languages. This was previously a clippy lint, clippy::double_neg, and is now available directly in Rust as double_negations. repr() attribute applied to invalid items are now correctly rejected. #![test] and #![rustfmt::skip] are no longer accepted in more places than intended. -O to mean -C opt-level=3 instead of -C opt-level=2 to match Cargo’s defaults. overflowing_literals under certain macro environments. i686-unknown-redox target with i586-unknown-redox. i686-unknown-hurd-gnu to Pentium 4. {aarch64-unknown,x86_64-pc}-nto-qnx710_iosock. For supporting Neutrino QNX 7.1 with io-socket network stack. {aarch64-unknown,x86_64-pc}-nto-qnx800. For supporting Neutrino QNX 8.0 (no_std-only). {x86_64,i686}-win7-windows-gnu. Intended for backwards compatibility with Windows 7. {x86_64,i686}-win7-windows-msvc are the Windows MSVC counterparts that already exist as Tier 3 targets. amdgcn-amd-amdhsa. x86_64-pc-cygwin. {mips,mipsel}-mti-none-elf. Initial bare-metal support. m68k-unknown-none-elf. armv7a-nuttx-{eabi,eabihf}, aarch64-unknown-nuttx, and thumbv7a-nuttx-{eabi,eabihf}. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
FromBytesWithNulError in CStr::from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, FromBytesWithNulError> was changed from an opaque struct to an enum, allowing users to examine why the conversion failed. RustcDecodable and RustcEncodable. --logfile option. std::fs::remove_file will now remove read-only files. {float}::next_down {float}::next_up <[_]>::get_disjoint_mut <[_]>::get_disjoint_unchecked_mut slice::GetDisjointMutError HashMap::get_disjoint_mut HashMap::get_disjoint_unchecked_mut NonZero::count_ones Vec::pop_if sync::Once::wait sync::Once::wait_force sync::OnceLock::wait These APIs are now stable in const contexts:
hint::black_box io::Cursor::get_mut io::Cursor::set_position str::is_char_boundary str::split_at str::split_at_checked str::split_at_mut str::split_at_mut_checked --package and --workspace are passed but the requested package is missing. This was previously silently ignored, which was considered a bug since missing packages should be reported. cargo login to avoid shell history leaks. SourceID comparisons. This may potentially change behavior if the canonicalized URL compares differently in alternative registries. wasm_c_abi future compatibility warning is now a hard error. Users of wasm-bindgen should upgrade to at least version 0.2.89, otherwise compilation will fail. #![no_start] and #![crate_id]. cenum_impl_drop_cast has been made into a hard error. This means it is now an error to cast a field-less enum to an integer if the enum implements Drop. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Feb 20, 2025 tracked by Updatify
#[diagnostic::do_not_recommend] unpredictable_function_pointer_comparisons lint to warn against function pointer comparisons #[no_mangle] and #[export_name] attributes. -Zpolymorphize has been removed, see https://github.com/rust-lang/compiler-team/issues/810 for some background. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
Panics in the standard library now have a leading library/ in their path
std::env::home_dir() on Windows now ignores the non-standard $HOME environment variable
It will be un-deprecated in a subsequent release.
BuildHasherDefault::new ptr::fn_addr_eq io::ErrorKind::QuotaExceeded io::ErrorKind::CrossesDevices {float}::midpoint {integer}::midpoint NonZeroU*::midpoint std::iter::Extend for tuples with arity 1 through 12,)) FromIterator<(A, ...)> for tuples with arity 1 through 12,)) std::task::Waker::noop These APIs are now stable in const contexts:
mem::size_of_val mem::align_of_val Layout::for_value Layout::align_to Layout::pad_to_align Layout::extend Layout::array std::mem::swap std::ptr::swap NonNull::new HashMap::with_hasher HashSet::with_hasher BuildHasherDefault::new <float>::recip <float>::to_degrees <float>::to_radians <float>::max <float>::min <float>::clamp <float>::abs <float>::signum <float>::copysign MaybeUninit::write CARGO_CFG_FEATURE to build scripts
rustc no longer treats the test cfg as a well known check-cfg, instead it is up to the build systems and users of --check-cfg[^check-cfg] to set it as a well known cfg using --check-cfg=cfg(test).
This is done to enable build systems like Cargo to set it conditionally, as not all source files are suitable for unit tests. Cargo (for now) unconditionally sets the test cfg as a well known cfg. [^check-cfg]: https://doc.rust-lang.org/nightly/rustc/check-cfg.html
Disable potentially incorrect type inference if there are trivial and non-trivial where-clauses
std::env::home_dir() has been deprecated for years, because it can give surprising results in some Windows configurations if the HOME environment variable is set (which is not the normal configuration on Windows). We had previously avoided changing its behavior, out of concern for compatibility with code depending on this non-standard configuration. Given how long this function has been deprecated, we’re now fixing its behavior as a bugfix. A subsequent release will remove the deprecation for this function.
Make core::ffi::c_char signedness more closely match that of the platform-default char
This changed c_char from an i8 to u8 or vice versa on many Tier 2 and 3 targets (mostly Arm and RISC-V embedded targets). The new definition may result in compilation failures but fixes compatibility issues with C.
The libc crate matches this change as of its 0.2.169 release.
Increase sparcv9-sun-solaris and x86_64-pc-solaris Solaris baseline to 11.4.
Show abi_unsupported_vector_types lint in future breakage reports
These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Jan 31, 2025 tracked by Updatify
Update Jan 9, 2025 tracked by Updatify
#[deny] inside #[forbid] as a no-op -Ctarget-feature is used to toggle features that can lead to unsoundness due to ABI mismatches / as the path separator for include!() in all cases on Windows raw (const|mut)) of a deref of a pointer (*ptr) is now safe extern "C" function --print host-tuple flag to print the host target tuple and affirm the “target tuple” terminology over “target triple” loongarch64-unknown-linux-{musl,ohos} unexpected_cfgs lint to also warn in external macros multivalue, reference-types, and tail-call target features wasm32v1-none target From<&mut {slice}> for Box/Rc/Arc<{slice}> <float>::copysign, <float>::abs, <float>::signum to core LowerExp and UpperExp implementations to NonZero FromStr for CString and TryFrom<CString> for String std::os::darwin has been made public Ipv6Addr::is_unique_local Ipv6Addr::is_unicast_link_local core::ptr::with_exposed_provenance core::ptr::with_exposed_provenance_mut <ptr>::addr <ptr>::expose_provenance <ptr>::with_addr <ptr>::map_addr <int>::isqrt <int>::checked_isqrt <uint>::isqrt NonZero::isqrt core::ptr::without_provenance core::ptr::without_provenance_mut core::ptr::dangling core::ptr::dangling_mut Pin::as_deref_mut These APIs are now stable in const contexts
AtomicBool::from_ptr AtomicPtr::from_ptr AtomicU8::from_ptr AtomicU16::from_ptr AtomicU32::from_ptr AtomicU64::from_ptr AtomicUsize::from_ptr AtomicI8::from_ptr AtomicI16::from_ptr AtomicI32::from_ptr AtomicI64::from_ptr AtomicIsize::from_ptr <ptr>::is_null <ptr>::as_ref <ptr>::as_mut Pin::new Pin::new_unchecked Pin::get_ref Pin::into_ref Pin::get_mut Pin::get_unchecked_mut Pin::static_ref Pin::static_mut LSX target feature for LoongArch Linux targets -Zprofile flag (“gcov-style” coverage instrumentation) has been removed. This does not affect the stable flags for coverage instrumentation (-Cinstrument-coverage) and profile-guided optimization (-Cprofile-generate, -Cprofile-use), which are unrelated and remain available. wasm32-wasi has been removed as the target is now named wasm32-wasip1. This completes the transition plan for this target following the introduction of wasm32-wasip1 in Rust 1.78. Compiler warnings on use of wasm32-wasi introduced in Rust 1.81 are now gone as well as the target is removed. &pin (mut|const) T is now parsed as a type which in theory could affect macro expansion results in some edge cases std::arch functions is no longer permitted to declare items or bodies (such as closures, inline consts, or async blocks). Update Nov 28, 2024 tracked by Updatify
&mut, *mut, &Cell, and *const Cell in const. const initializers. 'r#ident). ! const extern functions can now be defined for other calling conventions. expr_2021 macro fragment specifier in all editions. non_local_definitions lint now fires on less code and warns by default. -Csoft-float flag. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
PartialEq for ExitCode. catch_unwind can deal with foreign exceptions without UB, although the exact behavior is unspecified. Default for HashMap/HashSet iterators that don’t already have it. ptr::add/sub to not claim equivalence with offset. BufRead::skip_until ControlFlow::break_value ControlFlow::continue_value ControlFlow::map_break ControlFlow::map_continue DebugList::finish_non_exhaustive DebugMap::finish_non_exhaustive DebugSet::finish_non_exhaustive DebugTuple::finish_non_exhaustive ErrorKind::ArgumentListTooLong ErrorKind::Deadlock ErrorKind::DirectoryNotEmpty ErrorKind::ExecutableFileBusy ErrorKind::FileTooLarge ErrorKind::HostUnreachable ErrorKind::IsADirectory ErrorKind::NetworkDown ErrorKind::NetworkUnreachable ErrorKind::NotADirectory ErrorKind::NotSeekable ErrorKind::ReadOnlyFilesystem ErrorKind::ResourceBusy ErrorKind::StaleNetworkFileHandle ErrorKind::StorageFull ErrorKind::TooManyLinks Option::get_or_insert_default Waker::data Waker::new Waker::vtable char::MIN hash_map::Entry::insert_entry hash_map::VacantEntry::insert_entry These APIs are now stable in const contexts:
Cell::into_inner Duration::as_secs_f32 Duration::as_secs_f64 Duration::div_duration_f32 Duration::div_duration_f64 MaybeUninit::as_mut_ptr NonNull::as_mut NonNull::copy_from NonNull::copy_from_nonoverlapping NonNull::copy_to NonNull::copy_to_nonoverlapping NonNull::slice_from_raw_parts NonNull::write NonNull::write_bytes NonNull::write_unaligned OnceCell::into_inner Option::as_mut Option::expect Option::replace Option::take Option::unwrap Option::unwrap_unchecked Option::<&_>::copied Option::<&mut _>::copied Option::<Option<_>>::flatten Option::<Result<_, _>>::transpose RefCell::into_inner Result::as_mut Result::<&_, _>::copied Result::<&mut _, _>::copied Result::<Option<_>, _>::transpose UnsafeCell::get_mut UnsafeCell::into_inner array::from_mut char::encode_utf8 {float}::classify {float}::is_finite {float}::is_infinite {float}::is_nan {float}::is_normal {float}::is_sign_negative {float}::is_sign_positive {float}::is_subnormal {float}::from_bits {float}::from_be_bytes {float}::from_le_bytes {float}::from_ne_bytes {float}::to_bits {float}::to_be_bytes {float}::to_le_bytes {float}::to_ne_bytes mem::replace ptr::replace ptr::slice_from_raw_parts_mut ptr::write ptr::write_unaligned <*const _>::copy_to <*const _>::copy_to_nonoverlapping <*mut _>::copy_from <*mut _>::copy_from_nonoverlapping <*mut _>::copy_to <*mut _>::copy_to_nonoverlapping <*mut _>::write <*mut _>::write_bytes <*mut _>::write_unaligned slice::from_mut slice::from_raw_parts_mut <[_]>::first_mut <[_]>::last_mut <[_]>::first_chunk_mut <[_]>::last_chunk_mut <[_]>::split_at_mut <[_]>::split_at_mut_checked <[_]>::split_at_mut_unchecked <[_]>::split_first_mut <[_]>::split_last_mut <[_]>::split_first_chunk_mut <[_]>::split_last_chunk_mut str::as_bytes_mut str::as_mut_ptr str::from_utf8_unchecked_mut CARGO_MANIFEST_PATH environment variable, similar to CARGO_MANIFEST_DIR but pointing directly to the manifest file. package.autolib to the manifest, allowing [lib] auto-discovery to be disabled. # headers from the main item’s doc comment. This is similar to a third-party feature provided by the rustdoc-search-enhancements browser extension. Warn against function pointers using unsupported ABI strings.
Check well-formedness of the source type’s signature in fn pointer casts. This partly closes a soundness hole that comes when casting a function item to function pointer
Use equality instead of subtyping when resolving type dependent paths.
Linking on macOS now correctly includes Rust’s default deployment target. Due to a linker bug, you might have to pass MACOSX_DEPLOYMENT_TARGET or fix your #[link] attributes to point to the correct frameworks. See https://github.com/rust-lang/rust/pull/129369.
The future incompatibility lint deprecated_cfg_attr_crate_type_name has been made into a hard error. It was used to deny usage of #![crate_type] and #![crate_name] attributes in #![cfg_attr], which required a hack in the compiler to be able to change the used crate type and crate name after cfg expansion. Users can use --crate-type instead of #![cfg_attr(..., crate_type = "...")] and --crate-name instead of #![cfg_attr(..., crate_name = "...")] when running rustc/cargo rustc on the command line. Use of those two attributes outside of #![cfg_attr] continue to be fully supported.
Until now, paths into the sysroot were always prefixed with /rustc/$hash in diagnostics, codegen, backtrace, e.g.
thread 'main' panicked at 'hello world', map-panic.rs:2:50
stack backtrace:
0: std::panicking::begin_panic
at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/panicking.rs:616:12
1: map_panic::main::{{closure}}
at ./map-panic.rs:2:50
2: core::option::Option<T>::map
at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/core/src/option.rs:929:29
3: map_panic::main
at ./map-panic.rs:2:30
4: core::ops::function::FnOnce::call_once
at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/core/src/ops/function.rs:248:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.We want to change this behaviour such that, when
rust-srcsource files can be discovered, the virtual path is discarded and therefore the local path will be embedded, unless there is a--remap-path-prefixthat causes this local path to be remapped in the usual way.
#129687 implements this behaviour, when rust-src is present at compile time, rustc replaces /rustc/$hash with a real path into the local rust-src component with best effort. To sanitize this, users must explicitly supply --remap-path-prefix=<path to rust-src>=foo or not have the rust-src component installed.
The allow-by-default missing_docs lint used to disable itself when invoked through rustc --test/cargo test, resulting in #[expect(missing_docs)] emitting false positives due to the expectation being wrongly unfulfilled. This behavior has now been removed, which allows #[expect(missing_docs)] to be fulfilled in all scenarios, but will also report new missing_docs diagnostics for publicly reachable #[cfg(test)] items, integration test crate-level documentation, and publicly reachable items in integration tests.
The armv8r-none-eabihf target now uses the Armv8-R required set of floating-point features.
The sysroot no longer contains the std dynamic library in its top-level lib/ dir.
Update Oct 17, 2024 tracked by Updatify
addr_of(_mut)! macros and the newly stabilized &raw (const|mut) are now safe to use with all static items for<...> binder in trait bounds + use<'lt> opaque type precise capturing (RFC 3617) &raw const and &raw mut operators (RFC 2582) offset_of! T to be live when dropping [T; 0] const operands in inline assembly const fn aarch64-apple-ios-macabi and x86_64-apple-ios-macabi to Tier 2, and ship them with rustup -> ! aarch64-apple-darwin to Tier 1 aarch64-unknown-trusty and armv7-unknown-trusty as tier 3 targets wasm32-wasip2 to Tier 2. std::thread::Builder::spawn_unchecked std::str::CharIndices::offset std::option::Option::is_none_or [T]::is_sorted [T]::is_sorted_by [T]::is_sorted_by_key Iterator::is_sorted Iterator::is_sorted_by Iterator::is_sorted_by_key std::future::Ready::into_inner std::iter::repeat_n impl<T: Clone> DoubleEndedIterator for Take<Repeat<T>> impl<T: Clone> ExactSizeIterator for Take<Repeat<T>> impl<T: Clone> ExactSizeIterator for Take<RepeatWith<T>> impl Default for std::collections::binary_heap::Iter impl Default for std::collections::btree_map::RangeMut impl Default for std::collections::btree_map::ValuesMut impl Default for std::collections::vec_deque::Iter impl Default for std::collections::vec_deque::IterMut Rc<T>::new_uninit Rc<MaybeUninit<T>>::assume_init Rc<[T]>::new_uninit_slice Rc<[MaybeUninit<T>]>::assume_init Arc<T>::new_uninit Arc<MaybeUninit<T>>::assume_init Arc<[T]>::new_uninit_slice Arc<[MaybeUninit<T>]>::assume_init Box<T>::new_uninit Box<MaybeUninit<T>>::assume_init Box<[T]>::new_uninit_slice Box<[MaybeUninit<T>]>::assume_init core::arch::x86_64::_bextri_u64 core::arch::x86_64::_bextri_u32 core::arch::x86::_mm_broadcastsi128_si256 core::arch::x86::_mm256_stream_load_si256 core::arch::x86::_tzcnt_u16 core::arch::x86::_mm_extracti_si64 core::arch::x86::_mm_inserti_si64 core::arch::x86::_mm_storeu_si16 core::arch::x86::_mm_storeu_si32 core::arch::x86::_mm_storeu_si64 core::arch::x86::_mm_loadu_si16 core::arch::x86::_mm_loadu_si32 core::arch::wasm32::u8x16_relaxed_swizzle core::arch::wasm32::i8x16_relaxed_swizzle core::arch::wasm32::i32x4_relaxed_trunc_f32x4 core::arch::wasm32::u32x4_relaxed_trunc_f32x4 core::arch::wasm32::i32x4_relaxed_trunc_f64x2_zero core::arch::wasm32::u32x4_relaxed_trunc_f64x2_zero core::arch::wasm32::f32x4_relaxed_madd core::arch::wasm32::f32x4_relaxed_nmadd core::arch::wasm32::f64x2_relaxed_madd core::arch::wasm32::f64x2_relaxed_nmadd core::arch::wasm32::i8x16_relaxed_laneselect core::arch::wasm32::u8x16_relaxed_laneselect core::arch::wasm32::i16x8_relaxed_laneselect core::arch::wasm32::u16x8_relaxed_laneselect core::arch::wasm32::i32x4_relaxed_laneselect core::arch::wasm32::u32x4_relaxed_laneselect core::arch::wasm32::i64x2_relaxed_laneselect core::arch::wasm32::u64x2_relaxed_laneselect core::arch::wasm32::f32x4_relaxed_min core::arch::wasm32::f32x4_relaxed_max core::arch::wasm32::f64x2_relaxed_min core::arch::wasm32::f64x2_relaxed_max core::arch::wasm32::i16x8_relaxed_q15mulr core::arch::wasm32::u16x8_relaxed_q15mulr core::arch::wasm32::i16x8_relaxed_dot_i8x16_i7x16 core::arch::wasm32::u16x8_relaxed_dot_i8x16_i7x16 core::arch::wasm32::i32x4_relaxed_dot_i8x16_i7x16_add core::arch::wasm32::u32x4_relaxed_dot_i8x16_i7x16_add These APIs are now stable in const contexts:
std::task::Waker::from_raw std::task::Context::from_waker std::task::Context::waker {integer}::from_str_radix std::num::ParseIntError::kind explicit_builtin_cfgs_in_flags lint in order to prevent incoherent state, eg. windows cfg active but target is Linux based. The appropriate rustc flag should be used instead. binary_search which significantly improves performance (#128254). However when a sorted slice has multiple values which compare equal, the new implementation may select a different value among the equal ones than the old implementation. MSG_NOSIGNAL when writing to sockets. This avoids killing the process with SIGPIPE when writing to a closed socket, which matches the existing behavior on other UNIX targets. multivalue and reference-types are now both enabled by default. These two features both have subtle changes implied for generated WebAssembly binaries. For the multivalue feature, WebAssembly target support has changed when upgrading to LLVM 19. Support for generating functions with multiple returns no longer works and -Ctarget-feature=+multivalue has a different meaning than it did in LLVM 18 and prior. There is no longer any supported means to generate a module that has a function with multiple returns in WebAssembly from Rust source code. For the reference-types feature the encoding of immediates in the call_indirect, a commonly used instruction by the WebAssembly backend, has changed. Validators and parsers which don’t understand the reference-types proposal will no longer accept modules produced by LLVM due to this change in encoding of immediates. Additionally these features being enabled are encoded in the target_features custom section and may affect downstream tooling such as wasm-opt consuming the module. Generating a WebAssembly module that disables default features requires -Zbuild-std support from Cargo and more information can be found at rust-lang/rust#128511. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Sep 5, 2024 tracked by Updatify
extern "C" functions. & in elided self lifetimes. #[expect] for lints (RFC 2383), like #[allow] with a warning if the lint is not fulfilled. elided_lifetimes_in_associated_constant to deny. offset_from: always allow pointers to point to the same address. -Cinline-threshold=.... transmute size checks. box_pointers lint. no_std Xtensa targets: xtensa-esp32-none-elf, xtensa-esp32s2-none-elf, xtensa-esp32s3-none-elf std Xtensa targets: xtensa-esp32-espidf, xtensa-esp32s2-espidf, xtensa-esp32s3-espidf i686-unknown-redox arm64ec-pc-windows-msvc to Tier 2. loongarch64-unknown-linux-musl to Tier 2 with host tools. wasm32-wasi. (see compatibility note below) PanicInfo and std’s PanicInfo. (see compatibility note below) {Rc,Arc}::make_mut() to unsized types. driftsort and unstable ipnsort. All slice::sort* and slice::select_nth* methods are expected to see significant performance improvements. See the research project for more details. create_dir_all with respect to empty paths. Command‘s batch files argument escaping not working when file name has trailing whitespace or periods (CVE-2024-43402). core::error hint::assert_unchecked fs::exists AtomicBool::fetch_not Duration::abs_diff IoSlice::advance IoSlice::advance_slices IoSliceMut::advance IoSliceMut::advance_slices PanicHookInfo PanicInfo::message PanicMessage These APIs are now stable in const contexts:
char::from_u32_unchecked (function) char::from_u32_unchecked (method) CStr::count_bytes CStr::from_ptr .cargo_vcs_info.json is always included, even when --allow-dirty is passed. package.license-file and package.readme pointing to non-existent files during packaging. --release/--debug flag along with the --profile flag. lib.plugin key support in Cargo.toml. Rust plugin support has been deprecated for four years and was removed in 1.75.0.
Usage of the wasm32-wasi target will now issue a compiler warning and request users switch to the wasm32-wasip1 target instead. Both targets are the same, wasm32-wasi is only being renamed, and this change to the WASI target is being done to enable removing wasm32-wasi in January 2025.
We have renamed std::panic::PanicInfo to std::panic::PanicHookInfo. The old name will continue to work as an alias, but will result in a deprecation warning starting in Rust 1.82.0.
core::panic::PanicInfo will remain unchanged, however, as this is now a different type.
The reason is that these types have different roles: std::panic::PanicHookInfo is the argument to the panic hook in std context (where panics can have an arbitrary payload), while core::panic::PanicInfo is the argument to the #[panic_handler] in no_std context (where panics always carry a formatted message). Separating these types allows us to add more useful methods to these types, such as std::panic::PanicHookInfo::payload_as_str() and core::panic::PanicInfo::message().
The new sort implementations may panic if a type’s implementation of Ord (or the given comparison function) does not implement a total order as the trait requires. Ord‘s supertraits (PartialOrd, Eq, and PartialEq) must also be consistent. The previous implementations would not “notice” any problem, but the new implementations have a good chance of detecting inconsistencies, throwing a panic rather than returning knowingly unsorted data.
These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Jul 25, 2024 tracked by Updatify
exclusive_range_pattern feature Result in some scenarios repr(packed(1)) for_loops_over_fallibles lint to lint on fallibles behind references. -fuse-ld=lld on CCs that don’t support it ...) as a type in trait bounds -fuse-ld=lld foo.into_iter() resolving to &Box<[T]>: IntoIterator size_of and size_of_val and align_of and align_of_val to the prelude PathBuf::set_extension would add a path separator c_char on AIX to use the correct type offset_of! no longer returns a temporary str.to_lowercase correctly DEFAULT_MIN_STACK_SIZE to at least 64KiB impl Default for Rc<CStr> impl Default for Rc<str> impl Default for Rc<[T]> impl Default for Arc<str> impl Default for Arc<CStr> impl Default for Arc<[T]> impl IntoIterator for Box<[T]> impl FromIterator<String> for Box<str> impl FromIterator<char> for Box<str> LazyCell LazyLock Duration::div_duration_f32 Duration::div_duration_f64 Option::take_if Seek::seek_relative BinaryHeap::as_slice NonNull::offset NonNull::byte_offset NonNull::add NonNull::byte_add NonNull::sub NonNull::byte_sub NonNull::offset_from NonNull::byte_offset_from NonNull::read NonNull::read_volatile NonNull::read_unaligned NonNull::write NonNull::write_volatile NonNull::write_unaligned NonNull::write_bytes NonNull::copy_to NonNull::copy_to_nonoverlapping NonNull::copy_from NonNull::copy_from_nonoverlapping NonNull::replace NonNull::swap NonNull::drop_in_place NonNull::align_offset <[T]>::split_at_checked <[T]>::split_at_mut_checked str::split_at_checked str::split_at_mut_checked str::trim_ascii str::trim_ascii_start str::trim_ascii_end <[u8]>::trim_ascii <[u8]>::trim_ascii_start <[u8]>::trim_ascii_end Ipv4Addr::BITS Ipv4Addr::to_bits Ipv4Addr::from_bits Ipv6Addr::BITS Ipv6Addr::to_bits Ipv6Addr::from_bits Vec::<[T; N]>::into_flattened <[[T; N]]>::as_flattened <[[T; N]]>::as_flattened_mut These APIs are now stable in const contexts:
-Zcheck-cfg as always enabled check-cfg lint config for the unexpected_cfgs lint cargo update --precise <yanked> Cargo.toml when using cargo add cargo fix on IPv6-only networks custom_code_classes_in_docs feature - std::env::{set_var, remove_var} can no longer be converted to safe function pointers and no longer implement the Fn family of traits Self constructor from outer item is referenced in inner nested item indirect_structural_match and pointer_structural_match lints into hard errors where_clause_object_safety lint a regular object safety violation proc_macro_back_compat lint into a hard error. std::sync::ReentrantLockGuard<T> is no longer Sync if T: !Sync which means std::io::StdoutLock and std::io::StderrLock are no longer Sync FromIterator for Box<str>. Notably, this breaks versions of the time crate before 0.3.35, due to no longer inferring the implementation for Box<[_]>. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Jun 13, 2024 tracked by Updatify
const {} expressions. redundant_lifetimes lint to detect lifetimes which are semantically redundant. unnameable_types lint for public types that can’t be named. -C collapse-macro-debuginfo and #[collapse_debuginfo]. if and match expressions. const fn calls. refining_impl_trait lint. main from other modules or crates. impl Trait lifetime inference -C strip to only affect binaries, not artifacts like .pdb. -Crelro-level for controlling runtime link hardening. cfg names and values at compile-time with --check-cfg. Note that this only stabilizes the compiler part, the Cargo part is still unstable in this release. aarch64-apple-visionos and aarch64-apple-visionos-sim tier 3 targets. riscv32ima-unknown-none-elf tier 3 target. aarch64-pc-windows-gnullvm, i686-pc-windows-gnullvm, and x86_64-pc-windows-gnullvm. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
FromIterator for (impl Default + Extend, impl Default + Extend). {Div,Rem}Assign<NonZero<X>> on X. clone_from() in core/std. transmute between pointers and integers. {integer}::unchecked_add {integer}::unchecked_mul {integer}::unchecked_sub <[T]>::split_at_unchecked <[T]>::split_at_mut_unchecked <[u8]>::utf8_chunks str::Utf8Chunks str::Utf8Chunk <*const T>::is_aligned <*mut T>::is_aligned NonNull::is_aligned <*const [T]>::len <*mut [T]>::len <*const [T]>::is_empty <*mut [T]>::is_empty NonNull::<[T]>::is_empty CStr::count_bytes io::Error::downcast num::NonZero<T> path::absolute proc_macro::Literal::byte_character proc_macro::Literal::c_string These APIs are now stable in const contexts:
Atomic*::into_inner io::Cursor::new io::Cursor::get_ref io::Cursor::position io::empty io::repeat io::sink panic::Location::caller panic::Location::file panic::Location::line panic::Location::column lib.name, always normalizing to _. cargo add. gitoxide by default for listing files. / in docs to begin a search. RustcEncodable and RustcDecodable are soft-destabilized, to be removed from the prelude in next edition. wasm_c_abi future-incompatibility lint will warn about use of the non-spec-compliant C ABI. Use wasm-bindgen v0.2.88 to generate forward-compatible bindings. Update May 2, 2024 tracked by Updatify
#[cfg(target_abi = ...)] #[diagnostic] namespace and #[diagnostic::on_unimplemented] attribute illegal_floating_point_literal_pattern invalid_reference_casting to include references casting to bigger memory layout non_contiguous_range_endpoints lint for singleton gaps after exclusive ranges wasm_c_abi lint for use of older wasm-bindgen versions This lint currently only works when using Cargo. indirect_structural_match and pointer_structural_match lints to match RFC PartialEq-typed consts as patterns a hard error refining_impl_trait lint into _reachable, _internal variants where-bounds trait Trait: Auto {}: allow upcasting from dyn Trait to dyn Trait + Auto INVALID_DOC_ATTRIBUTES lint deny by default use checking Target changes:
wasm32-wasip1 tier 2 (without host tools) target wasm32-wasip2 tier 3 target wasm32-wasi-preview1-threads to wasm32-wasip1-threads arm64ec-pc-windows-msvc tier 3 target armv8r-none-eabihf tier 3 target for the Cortex-R52 loongarch64-unknown-linux-musl tier 3 target Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
RwLock with custom implementation char::is_grapheme_extended impl Read for &Stdin 'static lifetimes for several std::error::Error related implementations impl<Fd: AsFd> impl take ?Sized impl From<TryReserveError> for io::Error These APIs are now stable in const contexts:
rust-version when generating lockfile --charset via auto-detecting config value target.<triple>.rustdocflags officially impl Trait arithmetic_overflow lint const initializers This code was accidentally accepted. The fix can break generic code that borrows a value of unknown type, as there is currently no way to declare “this type has no interior mutability”. In the future, stabilizing the Freeze trait will allow proper support for such code. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Apr 9, 2024 tracked by Updatify
Update Mar 29, 2024 tracked by Updatify
Update Mar 21, 2024 tracked by Updatify
static_mut_refs to warn on references to mutable statics. unstable_features and make use of it in the compiler. soft_unstable in future breakage reports. i128 and u128 16-byte aligned on x86-based targets. --verbose in diagnostic output. unused_tuple_struct_fields lint into dead_code. fn/const items implied bounds and well-formedness check. riscv32{im|imafc}-unknown-none-elf targets to tier 2. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
array::each_ref array::each_mut core::net f32::round_ties_even f64::round_ties_even mem::offset_of! slice::first_chunk slice::first_chunk_mut slice::split_first_chunk slice::split_first_chunk_mut slice::last_chunk slice::last_chunk_mut slice::split_last_chunk slice::split_last_chunk_mut slice::chunk_by slice::chunk_by_mut Bound::map File::create_new Mutex::clear_poison RwLock::clear_poison cargo::. id format as PackageIDSpec. cargo-util-schemas as a crate. (). localStorage. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Feb 8, 2024 tracked by Updatify
ambiguous_wide_pointer_comparisons that supersedes clippy::vtable_address_comparisons #[must_use] pointers (in particular, Box<T> where T is #[must_use]) in unused_must_use. $message_type field to distinguish json diagnostic outputs Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
dbg!() std::hash::{DefaultHasher, RandomState} exports RwLockReadGuard and RwLockWriteGuard‘s Debug impls. File::create to work on hidden files Arc::unwrap_or_clone Rc::unwrap_or_clone Result::inspect Result::inspect_err Option::inspect type_name_of_val std::hash::{DefaultHasher, RandomState} These were previously available only through std::collections::hash_map. ptr::{from_ref, from_mut} ptr::addr_eq See Cargo release notes.
() with user-provided spans, which means that this lint will warn for user code. print_tts This change can break some naive manual parsing of token trees in proc macro code which expect a particular structure after .to_string(), rather than just arbitrary Rust code. IMPLIED_BOUNDS_ENTAILMENT into a hard error from a lint impl FromIterator for Vec for more details. default on free const items Update Dec 28, 2023 tracked by Updatify
async fn and return-position impl Trait in traits. &mut T in const contexts. usize/isize exhaustively with half-open ranges. char has the same size and alignment as u32. match. COINDUCTIVE_OVERLAP_IN_COHERENCE to deny, and warn in dependencies. riscv64-linux-android target spec. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
Waker::clone_from to avoid cloning Wakers unnecessarily. BufRead for VecDeque<u8>. FusedIterator for DecodeUtf16 when the inner iterator does. Not, Bit{And,Or}{,Assign} for IP addresses. Default for ExitCode. str::SplitInclusive‘s DoubleEndedIterator impl cfg(unix) platforms. Atomic*::from_ptr FileTimes FileTimesExt File::set_modified File::set_times IpAddr::to_canonical Ipv6Addr::to_canonical Option::as_slice Option::as_mut_slice pointer::byte_add pointer::byte_offset pointer::byte_offset_from pointer::byte_sub pointer::wrapping_byte_add pointer::wrapping_byte_offset pointer::wrapping_byte_sub These APIs are now stable in const contexts:
Ipv6Addr::to_ipv4_mapped MaybeUninit::assume_init_read MaybeUninit::zeroed mem::discriminant mem::zeroed [workspace.members] automatically. Cargo.toml manifests. #[repr(transparent)] if it isn’t part of the public ABI. const contexts. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Nov 16, 2023 tracked by Updatify
std::mem::Discriminant<T> does not depend on any lifetimes in T private_in_public lint with private_interfaces and private_bounds per RFC 2145. Read more in RFC 2145. #[repr(Rust)] async blocks impl_trait_projections PATH option for --print KIND=PATH *-apple-ios-macabi i686-pc-windows-gnullvm as a tier 3 target From<OwnedFd/Handle> for ChildStdin/out/err From<{&,&mut} [T; N]> for Vec<T> where T: Clone From<[T; N]> for Rc<[T]> and Arc<[T]> impl TryFrom<char> for u16 io_error_other feature Saturating type core::num::Saturating impl From<io::Stdout> for std::process::Stdio impl From<io::Stderr> for std::process::Stdio impl From<OwnedHandle> for std::process::Child{Stdin, Stdout, Stderr} impl From<OwnedFd> for std::process::Child{Stdin, Stdout, Stderr} std::ffi::OsString::from_encoded_bytes_unchecked std::ffi::OsString::into_encoded_bytes std::ffi::OsStr::from_encoded_bytes_unchecked std::ffi::OsStr::as_encoded_bytes std::io::Error::other impl TryFrom<char> for u16 impl<T: Clone, const N: usize> From<&[T; N]> for Vec<T> impl<T: Clone, const N: usize> From<&mut [T; N]> for Vec<T> impl<T, const N: usize> From<[T; N]> for Arc<[T]> impl<T, const N: usize> From<[T; N]> for Rc<[T]> These APIs are now stable in const contexts:
Cargo.toml, stabilize [lints] --keep-going build flag --help output cargo clean, add --dry-run flag and summary line at the end cargo update, make --package more convenient by being positional cargo update, clarify meaning of –aggressive as –recursive --dry-run --package flags) to resolve ambiguities .cargo/config.toml, merge lists in precedence order target.'cfg(..)'.linker --extern impl From<{&,&mut} [T; N]> for Vec<T> is known to cause some inference failures with overly-generic code. In those examples using the tui crate, the combination of AsRef<_> and Into<Vec> leaves the middle type ambiguous, and the new impl adds another possibility, so it now requires an explicit type annotation. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
None this cycle.
Update Oct 6, 2023 tracked by Updatify
clippy::fn_null_check lint as useless_ptr_null_checks. noop_method_call warn by default. try and async in macros. unconditional_recursion lint detect recursive drops. invalid_reference_casting lint is now deny-by-default (instead of allow-by-default) .comment section like GCC/Clang. extern "thiscall" and "thiscall-unwind" ABIs. wasm32-wasi-preview1-threads as a tier 2 target. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
Read, Write and Seek impls for Arc<File>. io::Sink into io::Empty. RefUnwindSafe for Backtrace ExitStatus implement Default impl SliceIndex<str> for (Bound<usize>, Bound<usize>) assert_eq! & assert_ne! panic messages. stat struct definitions. {integer}::div_ceil {integer}::next_multiple_of {integer}::checked_next_multiple_of std::ffi::FromBytesUntilNulError std::os::unix::fs::chown std::os::unix::fs::fchown std::os::unix::fs::lchown LocalKey::<Cell<T>>::get LocalKey::<Cell<T>>::set LocalKey::<Cell<T>>::take LocalKey::<Cell<T>>::replace LocalKey::<RefCell<T>>::with_borrow LocalKey::<RefCell<T>>::with_borrow_mut LocalKey::<RefCell<T>>::set LocalKey::<RefCell<T>>::take LocalKey::<RefCell<T>>::replace These APIs are now stable in const contexts:
These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
rustc_apfloat with the new version of the crate. internal_features lint for internal unstable features. Update Sep 20, 2023 tracked by Updatify
suspicious_double_ref_op lint when calling borrow() can_eq in derive(..) suggestion for missing method Update Sep 20, 2023 tracked by Updatify
Update Aug 24, 2023 tracked by Updatify
#![cfg(FALSE)] behaves on crate root clippy::undropped_manually_drops lint clippy::invalid_utf8_in_unchecked lint as invalid_from_utf8_unchecked and invalid_from_utf8 clippy::cast_ref_to_mut lint as invalid_reference_casting clippy::cmp_nan lint as invalid_nan_comparisons dyn Trait objects cfg-ed out items to mention them in diagnostics - is given as output file loongarch64-unknown-none* .eh_frame from being emitted for -C panic=abort Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
thread::{park, unpark} T: Sized bounds on BufReader<T>, BufWriter<T> and LineWriter<T> select_nth_unstable Ok on kill if process has already exited Vecs over different allocators {Arc,Rc,Weak}::ptr_eq ignore pointer metadata [] These APIs are now stable in const contexts:
-Zdoctest-in-workspace by default. When running each documentation test, the working directory is set to the root directory of the package the test belongs to. docs #12221 #12288 build.jobs parallelism back to the default. #12222 Display for Ipv6Addr for IPv4-compatible addresses mips*-unknown-linux-gnu* targets from host tier 2 to target tier 3 support. Update Jul 13, 2023 tracked by Updatify
raw-dylib, link_ordinal, import_name_type and -Cdlltool. clippy::{drop,forget}_{ref,copy} lints. Drop impl compatibility PlaceMention, making let _ = patterns more consistent with respect to the borrow checker. --print deployment-target flag for Apple targets. extern "C-unwind" and friends. The existing extern "C" etc. may change behavior for cross-language unwinding in a future release. *-linux-musl targets to 1.2.3, enabling time64 on 32-bit systems. debugger_visualizer for embedding metadata like Microsoft’s Natvis. Self respect tuple constructor privacy. apple-m1 as the target CPU for aarch64-apple-darwin. x86_64h-apple-darwin target. loongarch64-unknown-linux-gnu to Tier 2 with host tools. Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
Drop implementation, but panicking within a panic hook is now an immediate abort. From<&[T]> for Box<[T]> bound to T: Clone. T: Send bound in Error for mpsc::SendError<T> and TrySendError<T>. alloc::realloc to match Layout requirements that the size must not exceed isize::MAX. const {} syntax for std::thread_local. This syntax was stabilized in Rust 1.59, but not previously mentioned in release notes. CStr::is_empty BuildHasher::hash_one NonZeroI*::is_positive NonZeroI*::is_negative NonZeroI*::checked_neg NonZeroI*::overflowing_neg NonZeroI*::saturating_neg NonZeroI*::wrapping_neg Neg for NonZeroI* Neg for &NonZeroI* From<[T; N]> for (T...))) (array to N-tuple for N in 1..=12) From<(T...)> for [T; N]D) (N-tuple to array for N in 1..=12) windows::io::AsHandle for Box<T> windows::io::AsHandle for Rc<T> windows::io::AsHandle for Arc<T> windows::io::AsSocket for Box<T> windows::io::AsSocket for Rc<T> windows::io::AsSocket for Arc<T> These APIs are now stable in const contexts:
<*const T>::read <*const T>::read_unaligned <*mut T>::read <*mut T>::read_unaligned ptr::read ptr::read_unaligned <[T]>::split_at Cargo.toml. workspace_default_members to the output of cargo metadata. cargo new/cargo init. rustdoc::unescaped_backticks lint for broken inline code. ~~old~~ vs. ~new~) TypeId. Code that uses a constant TypeId in a pattern will potentially be broken. Known cases have already been fixed – in particular, users of the log crate’s kv_unstable feature should update to log v0.4.18 or later. sysroot crate to represent the standard library crates. This does not affect stable users, but may require adjustment in tools that build their own standard library. rustup. When Cargo detects it will run rustc pointing to a rustup proxy, it’ll try bypassing the proxy and use the underlying binary directly. There are assumptions around the interaction with rustup and RUSTUP_TOOLCHAIN. However, it’s not expected to affect normal users. RUSTUP_HOME and RUSTUP_TOOLCHAIN in the [env] configuration table. This is considered to be not a use case Cargo would like to support, since it will likely cause problems or lead to confusion. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Jun 1, 2023 tracked by Updatify
asm! operands format_args invocations to uses captures let _ = expr position. -Cdebuginfo=line-tables-only), which may eventually become the default for -Cdebuginfo=1. unused_allocation lint against Box::new too loongarch64-unknown-linux-gnu i586-pc-nto-qnx700 (QNX Neutrino RTOS, version 7.0), Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
Command prefer non-verbatim paths concat! Cell partial_cmp to implement tuple lt/le/ge/gt atomic_as_ptr nonnull_slice_from_raw_parts once_cell nonzero_min_max FnPtr trait that is implemented for all function pointers This extends Debug, Pointer, Hash, PartialEq, Eq, PartialOrd, and Ord implementations for function pointers with all ABIs. NonZero*::MIN/MAX BinaryHeap::retain Default for std::collections::binary_heap::IntoIter Default for std::collections::btree_map::{IntoIter, Iter, IterMut} Default for std::collections::btree_map::{IntoKeys, Keys} Default for std::collections::btree_map::{IntoValues, Values} Default for std::collections::btree_map::Range Default for std::collections::btree_set::{IntoIter, Iter} Default for std::collections::btree_set::Range Default for std::collections::linked_list::{IntoIter, Iter, IterMut} Default for std::vec::IntoIter Default for std::iter::Chain Default for std::iter::Cloned Default for std::iter::Copied Default for std::iter::Enumerate Default for std::iter::Flatten Default for std::iter::Fuse Default for std::iter::Rev Default for std::slice::Iter Default for std::slice::IterMut Rc::into_inner Arc::into_inner std::cell::OnceCell Option::is_some_and NonNull::slice_from_raw_parts Result::is_ok_and Result::is_err_and std::sync::atomic::Atomic*::as_ptr std::io::IsTerminal std::os::linux::net::SocketAddrExt std::os::unix::net::UnixDatagram::bind_addr std::os::unix::net::UnixDatagram::connect_addr std::os::unix::net::UnixDatagram::send_to_addr std::os::unix::net::UnixListener::bind_addr std::path::Path::as_mut_os_str std::sync::OnceLock CARGO_PKG_README sparse the default protocol for crates.io cargo logout libtest from supporting -Zunstable-options let _ = expr position. sign-ext and mutable-globals features in codegen This may cause incompatibility with older execution environments. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Apr 20, 2023 tracked by Updatify
Copy fields. cmpxchg16b target feature on x86 and x86_64. Self: Autotrait bounds on dyn-safe trait methods. str as containing [u8] for auto trait purposes. *-pc-windows-gnu on CI to mingw-w64 v10 and GCC 12.2. true and false as boolean flags in compiler arguments. repr(C) enums to c_int size. DispatchFromDyn for cell types, allowing downstream experimentation with custom method receivers. fmt::Arguments::as_str() may return Some(_) in more cases after optimization, subject to change. AsFd and AsRawFd for Rc. These APIs are now stable in const contexts:
SocketAddr::new SocketAddr::ip SocketAddr::port SocketAddr::is_ipv4 SocketAddr::is_ipv6 SocketAddrV4::new SocketAddrV4::ip SocketAddrV4::port SocketAddrV6::new SocketAddrV6::ip SocketAddrV6::port SocketAddrV6::flowinfo SocketAddrV6::scope_id cargo fix or cargo clippy --fix when compilation warnings are auto-fixable. cargo add if you try to install a library crate. CARGO_BIN_NAME environment variable also for binary examples. rustdoc::all group. !. rust-analysis component from rustup now only contains a warning placeholder. This was primarily intended for RLS, and the corresponding -Zsave-analysis flag has been removed from the compiler as well. default-features is set to false of a workspace dependency, and an inherited dependency of a member has default-features = true, Cargo will enable default features of that dependency. CARGO_HOME in the [env] configuration table. Cargo itself doesn’t pick up this value, but recursive calls to cargo would, which was not intended. tools = [...] is set in bootstrap.toml, we will respect a missing rustdoc in that list. By default rustdoc remains included. To retain the prior behavior explicitly add "rustdoc" to the list. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Mar 28, 2023 tracked by Updatify
@revoked and a better error message for @cert-authority in Cargo’s SSH host key verification Update Mar 27, 2023 tracked by Updatify
$prefix-clang as clang in linker detection code Update Mar 9, 2023 tracked by Updatify
alloc on stable without requiring the definition of a handler for allocation failure. Defining custom handlers is still unstable. efiapi calling convention. bindings_with_variant_name to deny-by-default armv7-sony-vita-newlibeabihf as a tier 3 target std::task::Context !Send and !Sync OnceWith & RepeatWith Vec -> VecDeque conversion guarantee {core,std}::pin::pin! impl From<bool> for {f32,f64} std::path::MAIN_SEPARATOR_STR impl DerefMut for PathBuf These APIs are now stable in const contexts:
cargo build --verbose tells you more about why it recompiles. net.git-fetch-with-cli option enabled SEMICOLON_IN_EXPRESSIONS_FROM_MACROS to future-incompat report --target by default for -Zgcc-ld=lld on wasm IMPLIED_BOUNDS_ENTAILMENT to Deny + ReportNow std::task::Context no longer implements Send and Sync These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
x86_64-pc-windows-msvc x86_64-apple-darwin Update Jan 26, 2023 tracked by Updatify
Sized predicates coinductive, allowing cycles. #[must_use] annotations on async fn also affect the Future::Output. cfg(FALSE). C or cdecl. verbatim. Added, updated, and removed targets:
powerpc64-ibm-aix. mipsel-sony-psx. no_std targets for the QNX Neutrino RTOS, aarch64-unknown-nto-qnx710 and x86_64-pc-nto-qnx710. aarch64-unknown-uefi, i686-unknown-uefi, and x86_64-unknown-uefi. linuxkernel targets (not used by the actual kernel). Refer to Rust’s platform support page for more information on Rust’s tiered platform support.
crossbeam-channel into std::sync::mpsc. Eq and Hash for ControlFlow. compiler_builtins with -C panic=abort. {integer}::checked_ilog {integer}::checked_ilog2 {integer}::checked_ilog10 {integer}::ilog {integer}::ilog2 {integer}::ilog10 NonZeroU*::ilog2 NonZeroU*::ilog10 NonZero*::BITS These APIs are now stable in const contexts:
repr(Rust) types now groups m*2^n-sized fields with equivalently aligned ones. This is intended to be an optimization, but it is also known to increase type sizes in a few cases for the placement of enum tags. As a reminder, the layout of repr(Rust) types is an implementation detail, subject to change. && and || will now drop temporaries from their sub-expressions in evaluation order, left-to-right. Previously, it was “twisted” such that the first expression dropped its temporaries last, after all of the other expressions dropped in order. -export-dynamic to wasm-ld. main is now mangled as __main_void on wasm32-wasi. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Jan 11, 2023 tracked by Updatify
Update Dec 15, 2022 tracked by Updatify
repr(Int) enums #[repr(u8)]
enum Foo {
A(u8) = 0,
B(i8) = 1,
C(bool) = 42,
}must_use on impl Trait for supertraits This makes impl ExactSizeIterator respect the existing #[must_use] annotation on Iterator. ..=X in patterns clippy::for_loops_over_fallibles lint into rustc sym operands in inline assembly #[derive(Default)] on a generic #[default] enum adding unnecessary Default bounds proc_macro::Span::source_text uX::{checked_add_signed, overflowing_add_signed, saturating_add_signed, wrapping_add_signed} iX::{checked_add_unsigned, overflowing_add_unsigned, saturating_add_unsigned, wrapping_add_unsigned} iX::{checked_sub_unsigned, overflowing_sub_unsigned, saturating_sub_unsigned, wrapping_sub_unsigned} BTreeSet::{first, last, pop_first, pop_last} BTreeMap::{first_key_value, last_key_value, first_entry, last_entry, pop_first, pop_last} AsFd implementations for stdio lock types on WASI. impl TryFrom<Vec<T>> for Box<[T; N]> core::hint::black_box Duration::try_from_secs_{f32,f64} Option::unzip std::os::fd cargo remove to remove dependencies from Cargo.toml cargo publish now waits for the new version to be downloadable before exiting See detailed release notes for more.
ProceduralMasquerade hack to older versions of rental __heap_base and __data_end on wasm32-wasi. __wasm_init_memory on WebAssembly. __tls_* on wasm32-unknown-unknown. libresolv in libstd on Darwin libstd no longer pull in libiconv.dylib on Darwin) order_dependent_trait_objects show up in future-breakage reports These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
Update Nov 3, 2022 tracked by Updatify
as casts of enums with #[non_exhaustive] variants let else let_underscore_drop and let_underscore_lock from Clippy breaking from arbitrary labeled blocks (“label-break-value”) MaybeUninit is the correct way to work with uninitialized memory. Drop impl on foreign ADTs special_module_name lint -C instrument-coverage New targets:
PartialEq::ne in derive(PartialEq) BCRYPT_RNG_ALG_HANDLE by default System with direct system allocator calls std::layout::Layout size must not overflow isize::MAX when rounded up to align This also changes the safety conditions on Layout::from_size_align_unchecked. std::backtrace::Backtrace Bound::as_ref std::io::read_to_string <*const T>::cast_mut <*mut T>::cast_const These APIs are now stable in const contexts:
std::layout::Layout size must not overflow isize::MAX when rounded up to align. This also changes the safety conditions on Layout::from_size_align_unchecked. PollFn now only implements Unpin if the closure is Unpin. This is a possible breaking change if users were relying on the blanket unpin implementation. See discussion on the PR for details of why this change was made. #![cfg_attr(..., crate_type = ...)] to set the crate type This strengthens the forward compatibility lint deprecated_cfg_attr_crate_type_name to deny. llvm-has-rust-patches allows setting the build system to treat the LLVM as having Rust-specific patches This option may need to be set for distributions that are building Rust with a patched LLVM via llvm-config, not the built-in LLVM. lld. For more information, see issue 102754. These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.
x.sh and x.ps1 shell scripts