rustdoc does not document Deref impls more than one level deep

[QuietMisdreavus]

use std::ops::Deref;

pub struct Base;

impl Base {
    pub fn asdf(&self) {}
}

pub struct LevelOne {
    pub base: Base,
}

impl Deref for LevelOne {
    type Target = Base;

    fn deref(&self) -> &Base {
        &self.base
    }
}

impl LevelOne {
    pub fn qwop(&self) {}
}

pub struct LevelTwo {
    pub base: LevelOne,
}

impl Deref for LevelTwo {
    type Target = LevelOne;

    fn deref(&self) -> &LevelOne {
        &self.base
    }
}

impl LevelTwo {
    pub fn custom() {}
}

In this example, LevelTwo derefs to LevelOne, which derefs to Base. However in the docs, only the methods from LevelOne are shown. We should recursively look for Deref impls on items we're collecting impls for via Deref.

[aldanor]

Just ran into this as well - a bit annoying, especially if Deref is used aggressively through the codebase, e.g. if there are multiple newtype layers like in the example above (which wouldn't be so uncommon). Are there any plans for this to be fixed?

[aldanor]

Ok, apparently there's #26207 which has been open for over 3 years with no changes...

[jyn514]

Duplicate of #26207