The next version of Rust has _significantly_ updated documentation here. A link for anyone reading before the next two weeks: <a href="https:&#x2F;&#x2F;doc.rust-lang.org&#x2F;beta&#x2F;std&#x2F;iter&#x2F;trait.Iterator.html" rel="nofollow">https:&#x2F;&#x2F;doc.rust-lang.org&#x2F;beta&#x2F;std&#x2F;iter&#x2F;trait.Iterator.html</a>