Rust 1.73.0 发布

Rust 1.73.0 稳定版已正式[发布](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fblog.rust-lang.org%2F2023%2F10%2F05%2FRust-1.73.0.html)，主要带来以下变化：

#### **Cleaner panic messages**

默认紧急处理程序生成的输出已更改为将 panic 消息放在单独一行，而不是用引号括起来。这可以使 panic 消息更易于阅读，如本示例所示：

```
fn main() {
    let file = "ferris.txt";
    panic!("oh no! {file:?} not found!");
}
```

Output before Rust 1.73：

```text
thread 'main' panicked at 'oh no! "ferris.txt" not found!', src/main.rs:3:5
```

Output starting in Rust 1.73：

```text
thread 'main' panicked at src/main.rs:3:5:
oh no! "ferris.txt" not found!
```

这在信息较长、包含嵌套引号或跨多行时尤其有用。

此外，`assert_eq` 和 `assert_ne` 产生的 panic 消息也已被修改，移动了自定义消息（第三个参数）并删除了一些不必要的标点符号，如下所示：

```
fn main() {
    assert_eq!("🦀", "🐟", "ferris is not a fish");
}
```

Output before Rust 1.73：

```text
thread 'main' panicked at 'assertion failed: `(left == right)`
 left: `"🦀"`,
right: `"🐟"`: ferris is not a fish', src/main.rs:2:5
```

Output starting in Rust 1.73：

```text
thread 'main' panicked at src/main.rs:2:5:
assertion `left == right` failed: ferris is not a fish
 left: "🦀"
right: "🐟"
```

#### **Thread local initialization**

[正如 RFC 3184](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fgithub.com%2Frust-lang%2Frfcs%2Fblob%2Fmaster%2Ftext%2F3184-thread-local-cell-methods.md) 中所提议的，`LocalKey<Cell<T>>` 和 `LocalKey<RefCell<T>>` 现在可以直接使用 `get()`、`set()`、`take()` 和 `replace()` 方法进行操作，而无需像一般 `LocalKey` 工作那样跳过 `with(|inner| ...)` 闭包。`LocalKey<T>` 是 `thread_local!`statics 的类型。

新方法使 common code 更加简洁，并避免了为新线程在 `thread_local!` 中指定的默认值运行额外的初始化代码。

```rust
thread_local! {
    static THINGS: Cell<Vec<i32>> = Cell::new(Vec::new());
}

fn f() {
    // before:
    THINGS.with(|i| i.set(vec![1, 2, 3]));
    // now:
    THINGS.set(vec![1, 2, 3]);

// ...

// before:
    let v = THINGS.with(|i| i.take());
    // now:
    let v: Vec<i32> = THINGS.take();
}
```

**Stabilized APIs**

-   [Unsigned `{integer}::div_ceil`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fprimitive.u32.html%23method.div_ceil)
-   [Unsigned `{integer}::next_multiple_of`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fprimitive.u32.html%23method.next_multiple_of)
-   [Unsigned `{integer}::checked_next_multiple_of`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fprimitive.u32.html%23method.checked_next_multiple_of)
-   [`std::ffi::FromBytesUntilNulError`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fffi%2Fstruct.FromBytesUntilNulError.html)
-   [`std::os::unix::fs::chown`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fos%2Funix%2Ffs%2Ffn.chown.html)
-   [`std::os::unix::fs::fchown`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fos%2Funix%2Ffs%2Ffn.fchown.html)
-   [`std::os::unix::fs::lchown`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fos%2Funix%2Ffs%2Ffn.lchown.html)
-   [`LocalKey::<Cell<T>>::get`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fthread%2Fstruct.LocalKey.html%23method.get)
-   [`LocalKey::<Cell<T>>::set`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fthread%2Fstruct.LocalKey.html%23method.set)
-   [`LocalKey::<Cell<T>>::take`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fthread%2Fstruct.LocalKey.html%23method.take)
-   [`LocalKey::<Cell<T>>::replace`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fthread%2Fstruct.LocalKey.html%23method.replace)
-   [`LocalKey::<RefCell<T>>::with_borrow`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fthread%2Fstruct.LocalKey.html%23method.with_borrow)
-   [`LocalKey::<RefCell<T>>::with_borrow_mut`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fthread%2Fstruct.LocalKey.html%23method.with_borrow_mut)
-   [`LocalKey::<RefCell<T>>::set`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fthread%2Fstruct.LocalKey.html%23method.set-1)
-   [`LocalKey::<RefCell<T>>::take`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fthread%2Fstruct.LocalKey.html%23method.take-1)
-   [`LocalKey::<RefCell<T>>::replace`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fstd%2Fthread%2Fstruct.LocalKey.html%23method.replace-1)

这些 API 现在在 const contexts 中是稳定的：

-   [`rc::Weak::new`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Falloc%2Frc%2Fstruct.Weak.html%23method.new)
-   [`sync::Weak::new`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Falloc%2Fsync%2Fstruct.Weak.html%23method.new)
-   [`NonNull::as_ref`](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fdoc.rust-lang.org%2Fstable%2Fcore%2Fptr%2Fstruct.NonNull.html%23method.as_ref)

详情可[查看官方公告](https://www.oschina.net/action/GoToLink?url=https%3A%2F%2Fblog.rust-lang.org%2F2023%2F10%2F05%2FRust-1.73.0.html)。