Simplify some iterator combinators

[compiler-errors]

Saw a flat_map().next() instead of a find_map() in some method probe code, so did a quick search for some similar usages.

[rustbot]

r? @cjgillot

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[rustbot]

Some changes occurred in compiler/rustc_codegen_gcc

cc @antoyo

[leonardo-m]

Is Clippy able to catch most of this stuff? :)

[compiler-errors]

No idea!

[compiler-errors]

@leonardo-m no -- clippy doesn't trigger on this:

fn main() {
    let x = vec![()];
    x.into_iter().flat_map(|_| Some(1)).next();
    // ^ should probably suggest `find_map`.
}

[matthiaskrgr]

https://github.com/rust-lang/rust-clippy/issues/new?assignees=&labels=A-lint&template=new_lint.yml :>

[compiler-errors]

So flat_map() over Option<_> is a pedantic lint already that suggests using filter_map, and then filter_map(..).next() is also a lint. So I'm not sure there's much else to suggest for clippy!

[vacuus]

In compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs, you can change .any(..) to .all(..) and remove both negations. Is Clippy missing this?

[SkiFire13]

In compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs, you can change .any(..) to .all(..) and remove both negations. Is Clippy missing this?

Note that there's also an && in the middle between two negations, so you need to remove all three negations and change the && to a ||. I guess that's too much for clippy.

[cjgillot]

This is a well-deserved simplifications. A few complementary ideas.

[cjgillot]

A few extra API nits and r=me.

[bors]

☔ The latest upstream changes (presumably #105752) made this pull request unmergeable. Please resolve the merge conflicts.

[compiler-errors]

Addressed comments in static_impl_trait.rs.

@bors r=cjgillot

[bors]

📌 Commit 2baee88 has been approved by cjgillot

It is now in the queue for this repository.