diff options
| -rw-r--r-- | src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024-structural.md | 26 | ||||
| -rw-r--r-- | src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024.md | 27 |
2 files changed, 47 insertions, 6 deletions
diff --git a/src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024-structural.md b/src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024-structural.md index bfdb579cd35..b2f59732801 100644 --- a/src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024-structural.md +++ b/src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024-structural.md @@ -9,12 +9,32 @@ The tracking issue for this feature is: [#123076] This feature is incomplete and not yet intended for general use. This implements experimental, Edition-dependent match ergonomics under consideration for inclusion -in Rust. -For more information, see the corresponding typing rules for [Editions 2021 and earlier] and for -[Editions 2024 and later]. +in Rust, allowing `&` patterns in more places. For example: +```rust,edition2024 +#![feature(ref_pat_eat_one_layer_2024_structural)] +#![allow(incomplete_features)] +# +# // Tests type equality in a way that avoids coercing `&&T` or `&mut T` to `&T`. +# trait Eq<T> {} +# impl<T> Eq<T> for T {} +# fn has_type<T>(_: impl Eq<T>) {} + +// `&` can match against a `ref` binding mode instead of a reference type: +let (x, &y) = &(0, 1); +has_type::<&u8>(x); +has_type::<u8>(y); + +// `&` can match against `&mut` references: +let &z = &mut 2; +has_type::<u8>(z); +``` + +For specifics, see the corresponding typing rules for [Editions 2021 and earlier] and for +[Editions 2024 and later]. For more information on binding modes, see [The Rust Reference]. For alternative experimental match ergonomics, see the feature [`ref_pat_eat_one_layer_2024`](./ref-pat-eat-one-layer-2024.md). [Editions 2021 and earlier]: https://nadrieril.github.io/typing-rust-patterns/?compare=false&opts1=AQEBAQIBAQEBAAAAAAAAAAAAAAAAAAA%3D&mode=rules&do_cmp=false [Editions 2024 and later]: https://nadrieril.github.io/typing-rust-patterns/?compare=false&opts1=AQEBAgEBAQEBAgIAAAAAAAAAAAAAAAA%3D&mode=rules&do_cmp=false +[The Rust Reference]: https://doc.rust-lang.org/reference/patterns.html#binding-modes diff --git a/src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024.md b/src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024.md index 0c90cec0dbd..f7c85eec2d2 100644 --- a/src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024.md +++ b/src/doc/unstable-book/src/language-features/ref-pat-eat-one-layer-2024.md @@ -9,12 +9,33 @@ The tracking issue for this feature is: [#123076] This feature is incomplete and not yet intended for general use. This implements experimental, Edition-dependent match ergonomics under consideration for inclusion -in Rust. -For more information, see the corresponding typing rules for [Editions 2021 and earlier] and for -[Editions 2024 and later]. +in Rust, allowing `&` patterns in more places. For example: + +```rust,edition2024 +#![feature(ref_pat_eat_one_layer_2024)] +#![allow(incomplete_features)] +# +# // Tests type equality in a way that avoids coercing `&&T` or `&mut T` to `&T`. +# trait Eq<T> {} +# impl<T> Eq<T> for T {} +# fn has_type<T>(_: impl Eq<T>) {} + +// `&` can match against a `ref` binding mode instead of a reference type: +let (x, &y) = &(0, 1); +has_type::<&u8>(x); +has_type::<u8>(y); + +// `&` can match against `&mut` references: +let &z = &mut 2; +has_type::<u8>(z); +``` + +For specifics, see the corresponding typing rules for [Editions 2021 and earlier] and for +[Editions 2024 and later]. For more information on binding modes, see [The Rust Reference]. For alternative experimental match ergonomics, see the feature [`ref_pat_eat_one_layer_2024_structural`](./ref-pat-eat-one-layer-2024-structural.md). [Editions 2021 and earlier]: https://nadrieril.github.io/typing-rust-patterns/?compare=false&opts1=AQEBAQIBAQABAAAAAQEBAAEBAAABAAA%3D&mode=rules&do_cmp=false [Editions 2024 and later]: https://nadrieril.github.io/typing-rust-patterns/?compare=false&opts1=AQEBAAABAQABAgIAAQEBAAEBAAABAAA%3D&mode=rules&do_cmp=false +[The Rust Reference]: https://doc.rust-lang.org/reference/patterns.html#binding-modes |