Lint name: while_let_loop

I tried this code:

(playground)

use std::{ sync::{Arc, RwLock}, thread::{sleep, spawn, JoinHandle}, time::Duration, }; // NOTE: the following function is a simplified version of the true function whose signature is generic. pub fn spawn_observer(observed: Arc<RwLock<Option<i32>>>, observer: fn(i32), interval: Duration) -> JoinHandle<()> { spawn(move || loop { if let Some(value) = *observed.read().unwrap() { observer(value); } else { break; } sleep(interval); }) }

I expected to see this happen: No warnings.

Instead, this happened: It suggests while let loop, which would cause observer to lock the observed, blocking the other threads that also read/mutate the observed.

Meta

• cargo clippy -V: clippy 0.1.51 (2fd73fa 2021-03-23)
• rustc -Vv:

  rustc 1.51.0 (2fd73fabe 2021-03-23) binary: rustc commit-hash: 2fd73fabe469357a12c2c974c140f67e7cdd76d0 commit-date: 2021-03-23 host: x86_64-unknown-linux-gnu release: 1.51.0 LLVM version: 11.0.1