needless_borrow suggestion doesn't compile #8367
Description
Summary
On the most recent nightly, the needless_borrow lint produces a suggestion that doesn't compile.
cargo +nightly-2022-01-29 clippy triggers this bug, but cargo +nightly-2022-01-28 clippy does not.
cc: @Jarcho (maybe?)
Reproducer
I tried this code:
fn main() { let s0 = String::new(); let mut chars = s0.chars(); let s1 = (&mut chars).take(0).collect::<String>(); println!("{}", s1); drop(chars); }I expected to see this happen:
Nothing.
Instead, this happened:
warning: this expression borrows a value the compiler would automatically borrow --> src/main.rs:4:14 | 4 | let s1 = (&mut chars).take(0).collect::<String>(); | ^^^^^^^^^^^^ help: change this to: `chars` | = note: `#[warn(clippy::needless_borrow)]` on by default = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow If you make the suggested change, you get:
error[E0382]: use of moved value: `chars` --> src/main.rs:6:10 | 3 | let mut chars = s0.chars(); | --------- move occurs because `chars` has type `Chars<'_>`, which does not implement the `Copy` trait 4 | let s1 = chars.take(0).collect::<String>(); | ------- `chars` moved due to this method call 5 | println!("{}", s1); 6 | drop(chars); | ^^^^^ value used here after move | note: this function takes ownership of the receiver `self`, which moves `chars` --> /home/smoelius/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/iter/traits/iterator.rs:1317:13 | 1317 | fn take(self, n: usize) -> Take<Self> | ^^^^ Version
rustc 1.60.0-nightly (e0a55f449 2022-01-28) binary: rustc commit-hash: e0a55f4491a729bffc63b402ba903d90858c806b commit-date: 2022-01-28 host: x86_64-unknown-linux-gnu release: 1.60.0-nightly LLVM version: 13.0.0 Additional Labels
No response