rustfmt does not collapse foo::{self}

[stepancheg]

use foo::self;

is collapsed to:

use foo;

But this:

use foo::{self};

is kept as is.

Used rustfmt from master (2022 Jun 22) with rustfmt.toml from rustfmt repo.

This behavior doesn't look intentional.

[ytmimi]

@stepancheg, thanks for reaching out.

I can't find any great documentation on the topic, but the two cases you mention aren't equivalent. The best resource I can link you to are the discussions in #3568, #4681, and rust-lang/rust#60941

A brief summary of the issue is that each import brings different things into scope so converting use foo::{self}; to use foo; could cause compilation problems. rustfmt can't safely make that transformation and leaves the import alone.

[stepancheg]

@ytmimi thank you for the explanations!