E0277 rust type_error ai_generated true

错误[E0277]：`Cell<i32>` 无法在线程间安全共享

error[E0277]: `Cell<i32>` cannot be shared between threads safely

ID: rust/e0277-send-not-implemented-for-arc-cell

其他格式: JSON · Markdown 中文 · English
85%修复率
88%置信度
1证据数
2023-01-15首次发现

版本兼容性

版本状态引入弃用备注
rustc 1.68 active — — —
rustc 1.75 active — — —
rustc 1.82 active — — —
rustc 1.90 active — — —

根因分析

尝试在线程间发送包含 `Cell`（它实现了 `!Send`）的类型，通常通过 `Arc<Cell<T>>` 或带有 `Cell` 字段的结构体。

English

Attempting to send a type containing Cell (which is !Send) across threads, typically via Arc<Cell<T>> or a struct with Cell field.

generic

官方文档

https://doc.rust-lang.org/stable/error_codes/E0277.html

解决方案

  1. Replace Cell with Mutex: `let shared = Arc::new(Mutex::new(42));` then use `shared.lock().unwrap()` to access the value. This makes the type Send because Mutex<T> is Send if T: Send.
  2. Use `std::cell::RefCell` with `Mutex` outer: `Arc<Mutex<RefCell<T>>>` if interior mutability is needed but the outer type must be Send.
  3. If the value is only read, use `Arc<std::sync::RwLock<T>>` for better concurrency.

无效尝试

常见但无效的做法:

  1. 95% 失败

    Arc<T> only implements Send if T: Send, and Cell is !Send, so Arc<Cell<i32>> remains !Send.

  2. 85% 失败

    Unsafe impl of Send for a type containing Cell is unsound; the compiler will still reject it unless you also disable the lint, and it may cause data races at runtime.

  3. 90% 失败

    The compiler correctly rejects because the closure captures a !Send type, even with move.