`chunks_exact_to_as_chunks` suggests iter() instead of iter_mut() for chunks_exact_mut and does not compile

Summary

chunks_exact_to_as_chunks suggests replacing chunks_exact_mut(N) with as_chunks_mut::<N>().0.iter() when it is (almost?) always wrong and does not compile, and should use iter_mut().

The suggestion is also significantly longer and less obvious than the initial code.

Reproducer

Code:

fn main() {
    let mut a = vec![1, 2, 3, 4, 5, 6];
    a.chunks_exact_mut(2).for_each(|c| c[0] = 2);
}

Current output:

a.as_chunks_mut::<2>().0.iter().for_each(|c| c[0] = 2);

Desired output:

a.as_chunks_mut::<2>().0.iter_mut().for_each(|c| c[0] = 2);

Version

rustc 1.98.0 (88d9e12ae 2026-08-18)
binary: rustc
commit-hash: 88d9e12ae178fab0fb5cc050a94da85685d449ea
commit-date: 2026-08-18
host: x86_64-unknown-linux-gnu
release: 1.98.0
LLVM version: 22.1.8

Additional Labels

@rustbot label +I-suggestion-causes-error