mutex_integer suggests using AtomicIsize over Mutex<i128>

[chorman0773]

Summary

mutex_integer suggests using AtomicIsize instead of Mutex, including when I store 1<<64 to it.

The value of course is not representable as isize, so will cause a panic at runtime if replaced (or require an as cast that truncates).

Lint Name

mutex_integer

Reproducer

I tried this code:

#![deny(clippy::nursery)]
use std::sync::Mutex;
let m = Mutex::<i128>::new(0);

std::thread::scope(|s|{
     s.spawn(|| *m.lock().unwrap() = 1<<64);
})

I saw this happen:

error: consider using an `AtomicIsize` instead of a `Mutex` here; if you just want the locking behavior and not the internal type, consider using `Mutex<()>`
 --> src/main.rs:4:9
  |
4 | let m = Mutex::<i128>::new(0);
  |         ^^^^^^^^^^^^^^^^^^^^^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#mutex_integer
note: the lint level is defined here
 --> src/main.rs:1:54
  |
1 | #![allow(dead_code, clippy::let_unit_value)] #![deny(clippy::nursery)]
  |                                                      ^^^^^^^^^^^^^^^
  = note: `#[deny(clippy::mutex_integer)]` implied by `#[deny(clippy::nursery)]`

error: consider using an `AtomicIsize` instead of a `Mutex` here; if you just want the locking behavior and not the internal type, consider using `Mutex<()>`
 --> src/main.rs:7:18
  |
7 |      s.spawn(|| *m.lock().unwrap() = 1<<64);
  |                  ^
  |
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#mutex_integer

error: could not compile `playground` due to 2 previous errors

I expected to see this happen:

No diagnostic.

Version

Nightly on play.rust-lang.org 2022-11-17 (via Ferris bot ?clippy command on rust community discord)

Additional Labels

No response

[chorman0773]

Is there a label for "Suggestion causes logic error"? I-suggestion-causes-error seems to imply ill-formed program.

[J-ZhengLi]

@rustbot claim