Requested by gdt@, taken from wip, any mismerges are mine and I'll follow up. While here pull in an additional fix from newer wip to disable the docs (they are absolutely huge and not all that useful). Version 1.54.0 (2021-07-29) ============================ Language ----------------------- - [You can now use macros for values in built-in attribute macros.][83366] While a seemingly minor addition on its own, this enables a lot of powerful functionality when combined correctly. Most notably you can now include external documentation in your crate by writing the following. ```rust #![doc = include_str!("README.md")] ``` You can also use this to include auto-generated modules: ```rust #[path = concat!(env!("OUT_DIR"), "/generated.rs")] mod generated; ``` - [You can now cast between unsized slice types (and types which contain unsized slices) in `const fn`.][85078] - [You can now use multiple generic lifetimes with `impl Trait` where the lifetimes don't explicitly outlive another.][84701] In code this means that you can now have `impl Trait<'a, 'b>` where as before you could only have `impl Trait<'a, 'b> where 'b: 'a`. Compiler ----------------------- - [Rustc will now search for custom JSON targets in `/lib/rustlib/<target-triple>/target.json` where `/` is the "sysroot" directory.][83800] You can find your sysroot directory by running `rustc --print sysroot`. - [Added `wasm` as a `target_family` for WebAssembly platforms.][84072] - [You can now use `#[target_feature]` on safe functions when targeting WebAssembly platforms.][84988] - [Improved debugger output for enums on Windows MSVC platforms.][85292] - [Added tier 3\* support for `bpfel-unknown-none` and `bpfeb-unknown-none`.][79608] Libraries ----------------------- - [`panic::panic_any` will now `#[track_caller]`.][85745] - [Added `OutOfMemory` as a variant of `io::ErrorKind`.][84744] - [ `proc_macro::Literal` now implements `FromStr`.][84717] - [The implementations of vendor intrinsics in core::arch have been significantly refactored.][83278] The main user-visible changes are a 50% reduction in the size of libcore.rlib and stricter validation of constant operands passed to intrinsics. The latter is technically a breaking change, but allows Rust to more closely match the C vendor intrinsics API. Stabilized APIs --------------- - [`BTreeMap::into_keys`] - [`BTreeMap::into_values`] - [`HashMap::into_keys`] - [`HashMap::into_values`] - [`arch::wasm32`] - [`VecDeque::binary_search`] - [`VecDeque::binary_search_by`] - [`VecDeque::binary_search_by_key`] - [`VecDeque::partition_point`] Cargo ----- - [Added the `--prune <spec>` option to `cargo-tree` to remove a package from the dependency graph.][cargo/9520] - [Added the `--depth` option to `cargo-tree` to print only to a certain depth in the tree ][cargo/9499] - [Added the `no-proc-macro` value to `cargo-tree --edges` to hide procedural macro dependencies.][cargo/9488] - [A new environment variable named `CARGO_TARGET_TMPDIR` is available.][cargo/9375] This variable points to a directory that integration tests and benches can use as a "scratchpad" for testing filesystem operations. Compatibility Notes ------------------- - [Mixing Option and Result via `?` is no longer permitted in closures for inferred types.][86831] - [Previously unsound code is no longer permitted where different constructors in branches could require different lifetimes.][85574] - As previously mentioned the [`std::arch` instrinsics now uses stricter const checking][83278] than before and may reject some previously accepted code. - [`i128` multiplication on Cortex M0+ platforms currently unconditionally causes overflow when compiled with `codegen-units = 1`.][86063] Version 1.53.0 (2021-06-17) ============================ Language ----------------------- - [You can now use unicode for identifiers.][83799] This allows multilingual identifiers but still doesn't allow glyphs that are not considered characters such as `~W~F` or `~_~@`. More specifically you can now use any identifier that matches the UAX #31 "Unicode Identifier and Pattern Syntax" standard. This is the same standard as languages like Python, however Rust uses NFC normalization which may be different from other languages. - [You can now specify "or patterns" inside pattern matches.][79278] Previously you could only use `|` (OR) on complete patterns. E.g. ```rust let x = Some(2u8); // Before matches!(x, Some(1) | Some(2)); // Now matches!(x, Some(1 | 2)); ``` - [Added the `:pat_param` `macro_rules!` matcher.][83386] This matcher has the same semantics as the `:pat` matcher. This is to allow `:pat` to change semantics to being a pattern fragment in a future edition. Compiler ----------------------- - [Updated the minimum external LLVM version to LLVM 10.][83387] - [Added Tier 3\* support for the `wasm64-unknown-unknown` target.][80525] - [Improved debuginfo for closures and async functions on Windows MSVC.][83941] Libraries ----------------------- - [Abort messages will now forward to `android_set_abort_message` on Android platforms when available.][81469] - [`slice::IterMut<'_, T>` now implements `AsRef<[T]>`][82771] - [Arrays of any length now implement `IntoIterator`.][84147] Currently calling `.into_iter()` as a method on an array will return `impl Iterator<Item=&T>`, but this may change in a future edition to change `Item` to `T`. Calling `IntoIterator::into_iter` directly on arrays will provide `impl Iterator<Item=T>` as expected. - [`leading_zeros`, and `trailing_zeros` are now available on all `NonZero` integer types.][84082] - [`{f32, f64}::from_str` now parse and print special values (`NaN`, `-0`) according to IEEE RFC 754.][78618] - [You can now index into slices using `(Bound<usize>, Bound<usize>)`.][77704] - [Add the `BITS` associated constant to all numeric types.][82565] Stabilised APIs --------------- - [`AtomicBool::fetch_update`] - [`AtomicPtr::fetch_update`] - [`BTreeMap::retain`] - [`BTreeSet::retain`] - [`BufReader::seek_relative`] - [`DebugStruct::non_exhaustive`] - [`Duration::MAX`] - [`Duration::ZERO`] - [`Duration::is_zero`] - [`Duration::saturating_add`] - [`Duration::saturating_mul`] - [`Duration::saturating_sub`] - [`ErrorKind::Unsupported`] - [`Option::insert`] - [`Ordering::is_eq`] - [`Ordering::is_ge`] - [`Ordering::is_gt`] - [`Ordering::is_le`] - [`Ordering::is_lt`] - [`Ordering::is_ne`] - [`OsStr::is_ascii`] - [`OsStr::make_ascii_lowercase`] - [`OsStr::make_ascii_uppercase`] - [`OsStr::to_ascii_lowercase`] - [`OsStr::to_ascii_uppercase`] - [`Peekable::peek_mut`] - [`Rc::decrement_strong_count`] - [`Rc::increment_strong_count`] - [`Vec::extend_from_within`] - [`array::from_mut`] - [`array::from_ref`] - [`cmp::max_by_key`] - [`cmp::max_by`] - [`cmp::min_by_key`] - [`cmp::min_by`] - [`f32::is_subnormal`] - [`f64::is_subnormal`] Cargo ----------------------- - [Cargo now supports git repositories where the default `HEAD` branch is not "master".][cargo/9392] This also includes a switch to the version 3 `Cargo.lock` format which can handle default branches correctly. - [macOS targets now default to `unpacked` split-debuginfo.][cargo/9298] - [The `authors` field is no longer included in `Cargo.toml` for new projects.][cargo/9282] Rustdoc ----------------------- - [Added the `rustdoc::bare_urls` lint that warns when you have URLs without hyperlinks.][81764] Compatibility Notes ------------------- - [Implement token-based handling of attributes during expansion][82608] - [`Ipv4::from_str` will now reject octal format IP addresses in addition to rejecting hexadecimal IP addresses.][83652] The octal format can lead to confusion and potential security vulnerabilities and [is no longer recommended][ietf6943]. - [The added `BITS` constant may conflict with external definitions.][85667] In particular, this was known to be a problem in the `lexical-core` crate, but they have published fixes for semantic versions 0.4 through 0.7. To update this dependency alone, use `cargo update -p lexical-core`. - Incremental compilation remains off by default, unless one uses the `RUSTC_FORCE_INCREMENTAL=1` environment variable added in 1.52.1. Internal Only ------------- These changes provide no direct user facing benefits, but represent significant improvements to the internals and overall performance of rustc and related tools. - [Rework the `std::sys::windows::alloc` implementation.][83065] - [rustdoc: Don't enter an infer_ctxt in get_blanket_impls for impls that aren't blanket impls.][82864] - [rustdoc: Only look at blanket impls in `get_blanket_impls`][83681] - [Rework rustdoc const type][82873]