Closed
Description
Summary
needless_pass_by_ref_mut lint is wrongfully emitted in some weird cases involving async functions and closures.
Note that #11551 was supposed to fix a similar issue, however the latest nightly still wrongfully emits a lint in the example below.
I did not debug it, but the lint seems to be extremely flaky, for example at one point during the minimization removing an unused use resulted in a lint not being emitted, at another point removing unused field caused a similar effect, but then removing another unused field brought the lint back...
Lint Name
needless_pass_by_ref_mut
Reproducer
I tried this code:
async fn _f(v: &mut Vec<()>) {
let x = || v.pop();
_ = || || x;
}(play)
I saw this happen:
warning: this argument is a mutable reference, but not used mutably
--> src/lib.rs:1:16
|
1 | async fn _f(v: &mut Vec<()>) {
| ^^^^^^^^^^^^ help: consider changing to: `&Vec<()>`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_pass_by_ref_mut
= note: `#[warn(clippy::needless_pass_by_ref_mut)]` on by default
I expected to see this happen: no warning, v is used mutably via .pop().
Version
1.75.0-nightly (2023-10-03 187b8131d4f760f856b2)
Additional Labels
No response