map_flatten removes comments between iterator methods with --fix :disappointed:

[matthiaskrgr]

Summary

.

Reproducer

I tried this code:

    vec.iter()
        // a lovely comment explaining the code in very detail
        .map(|x| x.iter())
        // the answer to life, the universe and everything could be here
        .flatten();

This is especially annoying when running --fix, clippy will just transform this
vec.iter().flat_map(|x| x.iter());
and eat all the comments.

Version

rustc 1.61.0-nightly (335ffbfa5 2022-03-11)
binary: rustc
commit-hash: 335ffbfa547df94ac236f5c56130cecf99c8d82b
commit-date: 2022-03-11
host: x86_64-unknown-linux-gnu
release: 1.61.0-nightly
LLVM version: 14.0.0

Additional Labels

No response

[J-ZhengLi]

Hi~ Sorry I keep mentioning this issue and deleting it cuz I was very sleepy and couldn't make up my mind🤦, you might wondering why there were many notifications or something...

Anyway, I just wanna mention that after PR #8520 , the comment above .map() should not be removed, but the one between it and .flatten() will still be removed. I can try find a way to keep it, but will that still make sense after the code below it is technically gone? 🤔