Releases · rust-lang/rust

You can now use the cfg(target_vendor) attribute. E.g. #[cfg(target_vendor="apple")] fn main() { println!("Hello Apple!"); }
Integer patterns such as in a match expression can now be exhaustive. E.g. You can have match statement on a u8 that covers 0..=255 and you would no longer be required to have a _ => unreachable!() case.

You can now have multiple patterns in if let and while let expressions. You can do this with the same syntax as a match expression. E.g.

enum Creature {
    Crab(String),
    Lobster(String),
    Person(String),
}

fn main() {
    let state = Creature::Crab("Ferris");

    if let Creature::Crab(name) | Creature::Person(name) = state {
        println!("This creature's name is: {}", name);
    }
}

You can now have irrefutable if let and while let patterns. Using this feature will by default produce a warning as this behaviour can be unintuitive. E.g. if let _ = 5 {}
You can now use let bindings, assignments, expression statements, and irrefutable pattern destructuring in const functions.

You can now call unsafe const functions. E.g.

const unsafe fn foo() -> i32 { 5 }
const fn bar() -> i32 {
    unsafe { foo() }
}

You can now specify multiple attributes in a cfg_attr attribute. E.g. #[cfg_attr(all(), must_use, optimize)]
You can now specify a specific alignment with the #[repr(packed)] attribute. E.g. #[repr(packed(2))] struct Foo(i16, i32); is a struct with an alignment of 2 bytes and a size of 6 bytes.
You can now import an item from a module as an _. This allows you to import a trait's impls, and not have the name in the namespace. E.g.
```
use std::io::Read as _;

// Allowed as there is only one `Read` in the module.
pub trait Read {}
```
You may now use Rc, Arc, and Pin as method receivers.

Compiler

Libraries

Stabilized APIs

Cargo

Compatibility Notes

The methods str::{trim_left, trim_right, trim_left_matches, trim_right_matches} are now deprecated in the standard library, and their usage will now produce a warning. Please use the str::{trim_start, trim_end, trim_start_matches, trim_end_matches} methods instead.
The Error::cause method has been deprecated in favor of Error::source which supports downcasting.
Libtest no longer creates a new thread for each test when --test-threads=1. It also runs the tests in deterministic order

Assets 2

10 Sep 08:08

rustbot

1.32.0

9fda7c2

Rust 1.32.0

Language

2018 edition

You can now use the ? operator in macro definitions. The ? operator allows you to specify zero or one repetitions similar to the * and + operators.
Module paths with no leading keyword like super, self, or crate, will now always resolve to the item (enum, struct, etc.) available in the module if present, before resolving to a external crate or an item the prelude. E.g.
```
enum Color { Red, Green, Blue }

use Color::*;
```

All editions

You can now match against PhantomData<T> types.
You can now match against literals in macros with the literal specifier. This will match against a literal of any type. E.g. 1, 'A', "Hello World"

Self can now be used as a constructor and pattern for unit and tuple structs. E.g.

struct Point(i32, i32);

impl Point {
    pub fn new(x: i32, y: i32) -> Self {
        Self(x, y)
    }

    pub fn is_origin(&self) -> bool {
        match self {
            Self(0, 0) => true,
            _ => false,
        }
    }
}

Self can also now be used in type definitions. E.g.

enum List<T>
where
    Self: PartialOrd<Self> // can write `Self` instead of `List<T>`
{
    Nil,
    Cons(T, Box<Self>) // likewise here
}

You can now mark traits with #[must_use]. This provides a warning if a impl Trait or dyn Trait is returned and unused in the program.

Compiler

The default allocator has changed from jemalloc to the default allocator on your system. The compiler itself on Linux & macOS will still use jemalloc, but programs compiled with it will use the system allocator.
Added the aarch64-pc-windows-msvc target.

Libraries

PathBuf now implements FromStr.
Box<[T]> now implements FromIterator<T>.

The dbg! macro has been stabilized. This macro enables you to easily debug expressions in your rust program. E.g.

let a = 2;
let b = dbg!(a * 2) + 1;
//      ^-- prints: [src/main.rs:4] a * 2 = 4
assert_eq!(b, 5);

The following APIs are now const functions and can be used in a const context.

Stabilized APIs

Assets 2

10 Sep 08:08

rustbot

1.31.1

b6c32da

Rust 1.31.1

Assets 2

10 Sep 05:53

rustbot

1.31.0

abe02ce

Rust 1.31.0

Language

🎉 This version marks the release of the 2018 edition of Rust. 🎉
New lifetime elision rules now allow for eliding lifetimes in functions and impl headers. E.g. impl<'a> Reader for BufReader<'a> {} can now be impl Reader for BufReader<'_> {}. Lifetimes are still required to be defined in structs.
You can now define and use const functions. These are currently a strict minimal subset of the const fn RFC. Refer to the language reference for what exactly is available.
You can now use tool lints, which allow you to scope lints from external tools using attributes. E.g. #[allow(clippy::filter_map)].
#[no_mangle] and #[export_name] attributes can now be located anywhere in a crate, not just in exported functions.
You can now use parentheses in pattern matches.

Compiler

Updated musl to 1.1.20

Libraries

You can now convert num::NonZero* types to their raw equivalents using the From trait. E.g. u8 now implements From<NonZeroU8>.
You can now convert a &Option<T> into Option<&T> and &mut Option<T> into Option<&mut T> using the From trait.
You can now multiply (*) a time::Duration by a u32.

Stabilized APIs

Cargo

Assets 2

10 Sep 05:53

rustbot

1.30.1

1433507

Rust 1.30.1

Assets 2

10 Sep 05:53

rustbot

1.30.0

da5f414

Rust 1.30.0

Language

Procedural macros are now available. These kinds of macros allow for more powerful code generation. There is a new chapter available in the Rust Programming Language book that goes further in depth.
You can now use keywords as identifiers using the raw identifiers syntax (r#), e.g. let r#for = true;
Using anonymous parameters in traits is now deprecated with a warning and will be a hard error in the 2018 edition.
You can now use crate in paths. This allows you to refer to the crate root in the path, e.g. use crate::foo; refers to foo in src/lib.rs.
Using a external crate no longer requires being prefixed with ::. Previously, using a external crate in a module without a use statement required let json = ::serde_json::from_str(foo); but can now be written as let json = serde_json::from_str(foo);.
You can now apply the #[used] attribute to static items to prevent the compiler from optimising them away, even if they appear to be unused, e.g. #[used] static FOO: u32 = 1;
You can now import and reexport macros from other crates with the use syntax. Macros exported with #[macro_export] are now placed into the root module of the crate. If your macro relies on calling other local macros, it is recommended to export with the #[macro_export(local_inner_macros)] attribute so users won't have to import those macros.
You can now catch visibility keywords (e.g. pub, pub(crate)) in macros using the vis specifier.
Non-macro attributes now allow all forms of literals, not just strings. Previously, you would write #[attr("true")], and you can now write #[attr(true)].
You can now specify a function to handle a panic in the Rust runtime with the #[panic_handler] attribute.

Compiler

Libraries

ManuallyDrop now allows the inner type to be unsized.

Stabilized APIs

Ipv4Addr::BROADCAST
Ipv4Addr::LOCALHOST
Ipv4Addr::UNSPECIFIED
Ipv6Addr::LOCALHOST
Ipv6Addr::UNSPECIFIED
Iterator::find_map

The following methods are replacement methods for trim_left, trim_right, trim_left_matches, and trim_right_matches, which will be deprecated in 1.33.0:
str::trim_end_matches
str::trim_end
str::trim_start_matches
str::trim_start

Cargo

cargo run doesn't require specifying a package in workspaces.
cargo doc now supports --message-format=json. This is equivalent to calling rustdoc --error-format=json.
Cargo will now provide a progress bar for builds.

Misc

Assets 2

10 Sep 08:08

rustbot

1.29.2

17a9dc7

Rust 1.29.2

Workaround for an aliasing-related LLVM bug, which caused miscompilation.
The rls-preview component on the windows-gnu targets has been restored.

Assets 2

Releases: rust-lang/rust

Rust 1.34.2

Uh oh!

Rust 1.34.1

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Rust 1.34.0

Language

Compiler

Libraries

Stabilized APIs

std & core

std

Cargo

Misc

Compatibility Notes

Uh oh!

Rust 1.33.0

Language

Compiler

Libraries

Stabilized APIs

Cargo

Compatibility Notes

Uh oh!

Rust 1.32.0

Language

2018 edition

All editions

Compiler

Libraries

Stabilized APIs

Uh oh!

Rust 1.31.1

Uh oh!

Rust 1.31.0

Language

Compiler

Libraries

Stabilized APIs

Cargo

Uh oh!

Rust 1.30.1

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Rust 1.30.0

Language

Compiler

Libraries

Stabilized APIs

Cargo

Misc

Uh oh!

Rust 1.29.2

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