Language
--------
- [Procedural macros are now available.][52081] These kinds of macros allow for
- more powerful code generation, there is a [new chapter available][proc-macros]
- in Rust Programming Language book that goes further in depth.
+ more powerful code generation. There is a [new chapter available][proc-macros]
+ in the Rust Programming Language book that goes further in depth.
- [You can now use keywords as identifiers using the raw identifiers
- syntax (`r#`).][53236] e.g. `let r#for = true;`
+ syntax (`r#`),][53236] 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.][53272]
- [You can now use `crate` in paths.][54404] 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 now no longer requires being prefixed with `::`.][54404]
- e.g. previously using a external crate in a module without a use statement
- required `let json = ::serde_json::from_str(foo);` can now be written
+ 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 `::`.][54404]
+ 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.][51363]
+ compiler from optimising them away, even if they appear to be unused,][51363]
e.g. `#[used] static FOO: u32 = 1;`
- [You can now import and reexport macros from other crates with the `use`
syntax.][50911] 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 that users won't have to
- import those macros.
-- [`mod.rs` files are now optional.][54146] Previously if you had a `foo` module
- with a `bar` submodule, you would have `src/foo/mod.rs` and `src/foo/bar.rs`.
- Now you can have `src/foo.rs` and `src/foo/bar.rs` to achieve the same effect.
+ 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.][53370]
-- [Non-macro attributes now allow all forms of literals not just
- strings.][53044] e.g. Previously you would write `#[attr("true")]` you can now
+- [Non-macro attributes now allow all forms of literals, not just
+ strings.][53044] 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.][51366]
- [`Ipv6Addr::UNSPECIFIED`]
- [`Iterator::find_map`]
- The following methods are a replacement methods for `trim_left`, `trim_right`,
- `trim_left_matches`, and `trim_right_matches`. Which will be deprecated
- in 1.33.0.
+ 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`]
- [`cargo run` doesn't require specifying a package in workspaces.][cargo/5877]
- [`cargo doc` now supports `--message-format=json`.][cargo/5878] This is
equivalent to calling `rustdoc --error-format=json`.
-- [You can specify which edition to create a project in cargo
- with `cargo new --edition`.][cargo/5984] Currently only `2015` is a
- valid option.
- [Cargo will now provide a progress bar for builds.][cargo/5995]
Misc
----
- [`rustdoc` allows you to specify what edition to treat your code as with the
`--edition` option.][54057]
-- [`rustdoc` now has the `--color` (Specify whether to output color) and
- `--error-format` (Specify error format e.g. `json`) options.][53003]
+- [`rustdoc` now has the `--color` (specify whether to output color) and
+ `--error-format` (specify error format, e.g. `json`) options.][53003]
- [We now distribute a `rust-gdbgui` script that invokes `gdbgui` with Rust
debug symbols.][53774]
- [Attributes from Rust tools such as `rustfmt` or `clippy` are now
- available.][53459] e.g. `#[rustfmt::skip]` will skip formatting the next item.
+ available,][53459] e.g. `#[rustfmt::skip]` will skip formatting the next item.
[50911]: https://github.com/rust-lang/rust/pull/50911/
[51363]: https://github.com/rust-lang/rust/pull/51363/
[54404]: https://github.com/rust-lang/rust/pull/54404/
[cargo/5877]: https://github.com/rust-lang/cargo/pull/5877/
[cargo/5878]: https://github.com/rust-lang/cargo/pull/5878/
-[cargo/5984]: https://github.com/rust-lang/cargo/pull/5984/
[cargo/5995]: https://github.com/rust-lang/cargo/pull/5995/
-[proc-macros]: https://doc.rust-lang.org/book/2018-edition/ch19-06-macros.html
+[proc-macros]: https://doc.rust-lang.org/nightly/book/2018-edition/ch19-06-macros.html
[`Ipv4Addr::BROADCAST`]: https://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#associatedconstant.BROADCAST
[`Ipv4Addr::LOCALHOST`]: https://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#associatedconstant.LOCALHOST
Libraries
---------
-- [`Once::call_once` now no longer requires `Once` to be `'static`.][52239]
+- [`Once::call_once` no longer requires `Once` to be `'static`.][52239]
- [`BuildHasherDefault` now implements `PartialEq` and `Eq`.][52402]
- [`Box<CStr>`, `Box<OsStr>`, and `Box<Path>` now implement `Clone`.][51912]
- [Implemented `PartialEq<&str>` for `OsString` and `PartialEq<OsString>`
Cargo
-----
-- [Cargo can silently fix some bad lockfiles ][cargo/5831] You can use
- `--locked` to disable this behaviour.
+- [Cargo can silently fix some bad lockfiles.][cargo/5831] You can use
+ `--locked` to disable this behavior.
- [`cargo-install` will now allow you to cross compile an install
- using `--target`][cargo/5614]
+ using `--target`.][cargo/5614]
- [Added the `cargo-fix` subcommand to automatically move project code from
2015 edition to 2018.][cargo/5723]
- [`cargo doc` can now optionally document private types using the
the specified level to that level.][52354] For example `--cap-lints warn`
will demote `deny` and `forbid` lints to `warn`.
- [`rustc` and `rustdoc` will now have the exit code of `1` if compilation
- fails, and `101` if there is a panic.][52197]
+ fails and `101` if there is a panic.][52197]
- [A preview of clippy has been made available through rustup.][51122]
- You can install the preview with `rustup component add clippy-preview`
+ You can install the preview with `rustup component add clippy-preview`.
Compatibility Notes
-------------------
- [`str::{slice_unchecked, slice_unchecked_mut}` are now deprecated.][51807]
Use `str::get_unchecked(begin..end)` instead.
-- [`std::env::home_dir` is now deprecated for its unintuitive behaviour.][51656]
+- [`std::env::home_dir` is now deprecated for its unintuitive behavior.][51656]
Consider using the `home_dir` function from
https://crates.io/crates/dirs instead.
- [`rustc` will no longer silently ignore invalid data in target spec.][52330]
be used as an identifier.
- [The dyn syntax is now available.][49968] This syntax is equivalent to the
bare `Trait` syntax, and should make it clearer when being used in tandem with
- `impl Trait`. Since it is equivalent to the following syntax:
+ `impl Trait` because it is equivalent to the following syntax:
`&Trait == &dyn Trait`, `&mut Trait == &mut dyn Trait`, and
`Box<Trait> == Box<dyn Trait>`.
- [Attributes on generic parameters such as types and lifetimes are
a different directory than `target` for placing compilation artifacts.
- [Cargo will be adding automatic target inference for binaries, benchmarks,
examples, and tests in the Rust 2018 edition.][cargo/5335] If your project specifies
- specific targets e.g. using `[[bin]]` and have other binaries in locations
+ specific targets, e.g. using `[[bin]]`, and have other binaries in locations
where cargo would infer a binary, Cargo will produce a warning. You can
- disable this feature ahead of time by setting any of the following `autobins`,
- `autobenches`, `autoexamples`, `autotests` to false.
+ disable this feature ahead of time by setting any of the following to false:
+ `autobins`, `autobenches`, `autoexamples`, `autotests`.
- [Cargo will now cache compiler information.][cargo/5359] This can be disabled by
setting `CARGO_CACHE_RUSTC_INFO=0` in your environment.
work.][49896] e.g. `::core::prelude::v1::StrExt::is_empty("")` will not
compile, `"".is_empty()` will still compile.
- [`Debug` output on `atomic::{AtomicBool, AtomicIsize, AtomicPtr, AtomicUsize}`
- will only print the inner type.][48553] e.g.
- `print!("{:?}", AtomicBool::new(true))` will print `true`
+ will only print the inner type.][48553] E.g.
+ `print!("{:?}", AtomicBool::new(true))` will print `true`,
not `AtomicBool(true)`.
- [The maximum number for `repr(align(N))` is now 2²⁹.][50378] Previously you
could enter higher numbers but they were not supported by LLVM. Up to 512MB
Compatibility Notes
-------------------
-- [The borrow checker was fixed to avoid unsoundness when using match ergonomics][51117]
+- [The borrow checker was fixed to avoid unsoundness when using match ergonomics.][51117]
[51117]: https://github.com/rust-lang/rust/issues/51117
Tools
-----
-- [RLS now works on Windows][50646]
-- [Rustfmt stopped badly formatting text in some cases][rustfmt/2695]
+- [RLS now works on Windows.][50646]
+- [Rustfmt stopped badly formatting text in some cases.][rustfmt/2695]
Compatibility Notes
--------
- [`fn main() -> impl Trait` no longer works for non-Termination
- trait][50656]
+ trait.][50656]
This reverts an accidental stabilization.
-- [`NaN > NaN` no longer returns true in const-fn contexts][50812]
-- [Prohibit using turbofish for `impl Trait` in method arguments][50950]
+- [`NaN > NaN` no longer returns true in const-fn contexts.][50812]
+- [Prohibit using turbofish for `impl Trait` in method arguments.][50950]
[50646]: https://github.com/rust-lang/rust/issues/50646
[50656]: https://github.com/rust-lang/rust/pull/50656
- [Closures now implement `Copy` and/or `Clone` if all captured variables
implement either or both traits.][49299]
- [The inclusive range syntax e.g. `for x in 0..=10` is now stable.][47813]
-- [The `'_` lifetime is now stable. The underscore lifetime can be used anywhere where a
+- [The `'_` lifetime is now stable. The underscore lifetime can be used anywhere a
lifetime can be elided.][49458]
- [`impl Trait` is now stable allowing you to have abstract types in returns
- or in function parameters.][49255] e.g. `fn foo() -> impl Iterator<Item=u8>` or
+ or in function parameters.][49255] E.g. `fn foo() -> impl Iterator<Item=u8>` or
`fn open(path: impl AsRef<Path>)`.
- [Pattern matching will now automatically apply dereferences.][49394]
- [128-bit integers in the form of `u128` and `i128` are now stable.][49101]
- [`main` can now return `Result<(), E: Debug>`][49162] in addition to `()`.
- [A lot of operations are now available in a const context.][46882] E.g. You
can now index into constant arrays, reference and dereference into constants,
- and use Tuple struct constructors.
-- [Fixed entry slice patterns are now stable.][48516] e.g.
+ and use tuple struct constructors.
+- [Fixed entry slice patterns are now stable.][48516] E.g.
```rust
let points = [1, 2, 3, 4];
match points {
Compiler
--------
- [Enabled `TrapUnreachable` in LLVM which should mitigate the impact of
- undefined behaviour.][45920]
+ undefined behavior.][45920]
- [rustc now suggests renaming import if names clash.][45660]
- [Display errors/warnings correctly when there are zero-width or
wide characters.][45711]
projects / rust.git / blobdiff