Associated types implementation with where clause are not formatted

[ia0]

trait Foo {
    type Bar;
}

impl Foo for () {
    // The following line doesn't get formatted.
    type Bar = ()    where u8: Copy;
}

playground

Removing the where clause restores formatting, so this looks specific to where clause in associated types.

[ytmimi]

@ia0 thanks for the report. Confirming I can reproduce this with rustfmt 1.5.2-nightly (4aacac8e 2023-04-09).

The issue here might be that we haven't defined how to format associated types when the where clause comes after the type.

There doesn't seem to be anything defined in the Style Guide docs for Associated types. @calebcartwright is this something that needs to be brought to t-style's attention? Maybe the Style Guide docs should be brought closer in line with the Rust Reference Associated Types docs

It looks like we can format the deprecated form:

Input

impl Foo for () {
    // The following line doesn't get formatted.
    type Bar = ()    where u8: Copy;

    // The following is formatted.
    type Baz where u8:      Copy   =    ();
}

Output

impl Foo for () {
    // The following line doesn't get formatted.
    type Bar = ()    where u8: Copy;
    type Baz
    where
        u8: Copy,
    = ();
}

[ytmimi]

After looking into it I think this is a duplicate of #5580

[ia0]

After looking into it I think this is a duplicate of #5580

I confirm. Feel free to close this issue as duplicate. I subscribed to the other one.

[ytmimi]

Thanks for confirming this is a duplicate