Canonicalise use foo::{self} with merge_derives

[ndmitchell]

With merge_derives enabled, rustfmt (rustfmt 1.4.22-nightly (97d0301 2020-10-04)) changes:

• use foo::{bar} to use foo::bar
• use foo::self to use foo

But it doesn't change use foo::{self} to use foo. Such statements can arise through automated refactoring and would be useful to transform.

[goffrie]

I also find that converting foo::{self} to foo has always been what I want, but this is intentional as it is technically an unsound conversion: rust-lang/rust#60941 / #3753

[calebcartwright]

I also find that converting foo::{self} to foo has always been what I want, but this is intentional as it is technically an unsound conversion: rust-lang/rust#60941 / #3753

Correct. Thanks @goffrie!

Going to go ahead and close, but thanks for reaching out @ndmitchell

[ndmitchell]

Is foo::{self} to foo::self unsound? That isn't done and would be reasonable from reading above, I think.

[goffrie]

`foo::self` isn't legal Rust syntax, oddly enough.

…

On Thu., Dec. 17, 2020, 02:52 Neil Mitchell, ***@***.***> wrote: Is foo::{self} to foo::self unsound? That isn't done and would be reasonable from reading above, I think. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#4574 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAJO2TX26Y6MS3HCYEDOJMLSVHBEXANCNFSM4ULVHONA> .

[calebcartwright]

foo::self isn't legal Rust syntax, oddly enough.

Correct, we actually used to have a bug where rustfmt would do the requested behavior (#3808). The requested feature is definitely not something we should do