Language
--------
- [You can now use the `cfg(target_vendor)` attribute.][57465] E.g.
- `#[cfg(target_vendor="linux")] fn main() { println!("Hello Linux!"); }`
+ `#[cfg(target_vendor="apple")] fn main() { println!("Hello Apple!"); }`
- [Integer patterns such as in a match expression can now be exhaustive.][56362]
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 would no longer be required to have a `_ => unreachable!()` case.
- [You can now have multiple patterns in `if let` and `while let`
expressions.][57532] You can do this with the same syntax as a `match`
expression. E.g.
let state = Creature::Crab("Ferris");
if let Creature::Crab(name) | Creature::Person(name) = state {
- println!("This creature's name is: {}", name);
+ println!("This creature's name is: {}", name);
}
}
```
- [You can now have irrefutable `if let` and `while let` patterns.][57535] 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 pattern destructuring in
- const functions.][57175]
+- [You can now use `let` bindings, assignments, expression statements,
+ and irrefutable pattern destructuring in const functions.][57175]
- [You can now call unsafe const functions.][57067] E.g.
```rust
const unsafe fn foo() -> i32 { 5 }
const fn bar() -> i32 {
- unsafe { foo() }
+ unsafe { foo() }
}
```
- [You can now specify multiple attributes in a `cfg_attr` attribute.][57332]
// Allowed as there is only one `Read` in the module.
pub trait Read {}
```
-- [`extern` functions will now abort by default when panicking.][55982]
- This was previously undefined behaviour.
+- [You may now use `Rc`, `Arc`, and `Pin` as method receivers][56805].
Compiler
--------
Libraries
---------
-- [The functions `overflowing_{add, sub, mul, shl, shr}` are now `const`
+- [The methods `overflowing_{add, sub, mul, shl, shr}` are now `const`
functions for all numeric types.][57566]
-- [The functions `rotate_left`, `rotate_right`, and `wrapping_{add, sub, mul, shl, shr}`
+- [The methods `rotate_left`, `rotate_right`, and `wrapping_{add, sub, mul, shl, shr}`
are now `const` functions for all numeric types.][57105]
-- [The functions `is_positive` and `is_negative` are now `const` functions for
+- [The methods `is_positive` and `is_negative` are now `const` functions for
all signed numeric types.][57105]
- [The `get` method for all `NonZero` types is now `const`.][57167]
-- [The functions `count_ones`, `count_zeros`, `leading_zeros`, `trailing_zeros`,
+- [The methods `count_ones`, `count_zeros`, `leading_zeros`, `trailing_zeros`,
`swap_bytes`, `from_be`, `from_le`, `to_be`, `to_le` are now `const` for all
numeric types.][57234]
- [`Ipv4Addr::new` is now a `const` function][57234]
Stabilized APIs
---------------
- [`unix::FileExt::read_exact_at`]
-- [`unix::FileExt::write_exact_at`]
+- [`unix::FileExt::write_all_at`]
- [`Option::transpose`]
- [`Result::transpose`]
- [`convert::identity`]
Compatibility Notes
-------------------
-- The functions `str::{trim_left, trim_right, trim_left_matches, trim_right_matches}`
- are now offically deprecated, and their usage will now produce a warning. Please use the
- `str::{trim_start, trim_end, trim_start_matches, trim_end_matches}` functions instead.
+- 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.
-[57615]: https://github.com/rust-lang/rust/pull/57615/
-[57465]: https://github.com/rust-lang/rust/pull/57465/
-[57532]: https://github.com/rust-lang/rust/pull/57532/
-[57535]: https://github.com/rust-lang/rust/pull/57535/
-[57566]: https://github.com/rust-lang/rust/pull/57566/
+[55982]: https://github.com/rust-lang/rust/pull/55982/
+[56303]: https://github.com/rust-lang/rust/pull/56303/
+[56351]: https://github.com/rust-lang/rust/pull/56351/
+[56362]: https://github.com/rust-lang/rust/pull/56362
+[56642]: https://github.com/rust-lang/rust/pull/56642/
+[56769]: https://github.com/rust-lang/rust/pull/56769/
+[56805]: https://github.com/rust-lang/rust/pull/56805
+[56947]: https://github.com/rust-lang/rust/pull/56947/
+[57049]: https://github.com/rust-lang/rust/pull/57049/
+[57067]: https://github.com/rust-lang/rust/pull/57067/
+[57105]: https://github.com/rust-lang/rust/pull/57105
[57130]: https://github.com/rust-lang/rust/pull/57130/
[57167]: https://github.com/rust-lang/rust/pull/57167/
[57175]: https://github.com/rust-lang/rust/pull/57175/
[57234]: https://github.com/rust-lang/rust/pull/57234/
[57332]: https://github.com/rust-lang/rust/pull/57332/
-[56947]: https://github.com/rust-lang/rust/pull/56947/
-[57049]: https://github.com/rust-lang/rust/pull/57049/
-[57067]: https://github.com/rust-lang/rust/pull/57067/
-[56769]: https://github.com/rust-lang/rust/pull/56769/
-[56642]: https://github.com/rust-lang/rust/pull/56642/
-[56303]: https://github.com/rust-lang/rust/pull/56303/
-[56351]: https://github.com/rust-lang/rust/pull/56351/
-[55982]: https://github.com/rust-lang/rust/pull/55982/
-[56362]: https://github.com/rust-lang/rust/pull/56362
-[57105]: https://github.com/rust-lang/rust/pull/57105
+[57465]: https://github.com/rust-lang/rust/pull/57465/
+[57532]: https://github.com/rust-lang/rust/pull/57532/
+[57535]: https://github.com/rust-lang/rust/pull/57535/
+[57566]: https://github.com/rust-lang/rust/pull/57566/
+[57615]: https://github.com/rust-lang/rust/pull/57615/
[cargo/6484]: https://github.com/rust-lang/cargo/pull/6484/
[`unix::FileExt::read_exact_at`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html#method.read_exact_at
-[`unix::FileExt::write_exact_at`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html#method.write_exact_at
+[`unix::FileExt::write_all_at`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html#method.write_all_at
[`Option::transpose`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.transpose
[`Result::transpose`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.transpose
[`convert::identity`]: https://doc.rust-lang.org/std/convert/fn.identity.html
- [You can now match against literals in macros with the `literal`
specifier.][56072] 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.][56365] E.g.
+- [Self can now be used as a constructor and pattern for unit and tuple structs.][56365] E.g.
```rust
struct Point(i32, i32);
Language
--------
-- 🎉 [This version marks the release of the 2018 edition of Rust.][54057] 🎉
+- 🎉 [This version marks the release of the 2018 edition of Rust.][54057] 🎉
- [New lifetime elision rules now allow for eliding lifetimes in functions and
impl headers.][54778] E.g. `impl<'a> Reader for BufReader<'a> {}` can now be
`impl Reader for BufReader<'_> {}`. Lifetimes are still required to be defined
projects / rust.git / blobdiff