Macros can not parse and expand to associated types

[Kimundi]

macro_rules! items {
    () => {
        type A = ();
        fn a() {}
    }
}

trait Foo {
    type A;
    fn a();
}

impl Foo for () {
    items!();
}

fn main() {

}

<anon>:3:9: 3:13 error: expected one of `extern`, `fn`, or `unsafe`, found `type`
<anon>:3         type A = ();
                 ^~~~

[kmcallister]

Mm, we have "method macros" but now there are other things that can go in a trait.

[Kimundi]

Seems to be fixed by #23265, but I don't see tests for it specifically, so I guess this needs tests.