- label: "unsized_tuple_coercion",

- description: r##"# `unsized_tuple_coercion`

-

-The tracking issue for this feature is: [#42877]

-

-[#42877]: https://github.com/rust-lang/rust/issues/42877

-

-------------------------

-

-This is a part of [RFC0401]. According to the RFC, there should be an implementation like this:

-

-```rust,ignore (partial-example)

-impl<..., T, U: ?Sized> Unsized<(..., U)> for (..., T) where T: Unsized<U> {}

-```

-

-This implementation is currently gated behind `#[feature(unsized_tuple_coercion)]` to avoid insta-stability. Therefore you can use it like this:

-

-```rust

-#![feature(unsized_tuple_coercion)]

-

-fn main() {

- let x : ([i32; 3], [i32; 3]) = ([1, 2, 3], [4, 5, 6]);

- let y : &([i32; 3], [i32]) = &x;

- assert_eq!(y.1[0], 4);

-}

-```

-

-[RFC0401]: https://github.com/rust-lang/rfcs/blob/master/text/0401-coercions.md

-"##,

- default_severity: Severity::Allow,

- warn_since: None,

- deny_since: None,

- },

- Lint {