Generalize iter_cloned_collect to .copied()

[kpreid]

I ran Clippy on some previously unlinted code and found that it reported that

some_slice.iter().cloned().collect::<Vec<_>>()

could be replaced with some_slice.to_vec(), but, did not report cases where I had happened to write

some_slice.iter().copied().collect::<Vec<_>>()

instead. Perhaps it would make sense to generalize iter_cloned_collect to also detect uses of .copied(), or add a corresponding lint if they should be kept separate for some reason.

[giraffate]

Thanks for suggesting enhancement! But it seems to be a duplicate of #3870, so I'm closing this.

[kpreid]

I think these are different issues: that issue talks about a lint replacing .cloned() with .copied(). In this issue, I am proposing that the lint would recommend replacing a chain containing .copied() with .to_vec().

Sorry if my two-code-blocks formatting made it overly easy to read this as proposing the first block being replaced with the second.

(Incidentally, I checked the standard library source and .to_vec() uses Copy when available, so this would not have any performance regression.)

[giraffate]

Oh, sorry for my misunderstanding. I reopen this.

[HarrisonMc555]

I'll try implementing this! @rustbot claim