Type inheritance in traits is not mentioned

[Yanpas]

Don't know how to name this feature, so example:

use std::fmt::Display;

pub trait Footrait {
    type Owned: Display;
}

struct AA(i32);

impl Footrait for AA {
	type Owned = String;
}

This is not mentioned anywhere, met this in standard library alloc::borrow::ToOwned

[Havvy]

I'd call it "Trait bounds shorthand on associated type declarations". It's short for type Owned where Owned: Display;

[Centril]

I'd call it "Trait bounds shorthand on associated type declarations". It's short for type Owned where Owned: Display;

This will only actually be true once we have implied bounds; see https://github.com/rust-lang/rfcs/blob/master/text/2289-associated-type-bounds.md#an-alternative-desugaring-of-bounds-on-associated-types for a discussion.