Rollup merge of #43074 - SimonSapin:iter, r=aturon

Forward more Iterator methods

This allows in more cases to take advantage of specific (possibly more optimized) impls of these methods, rather than the default one defined for all `Iterator`s.

I also wanted to do this for `&mut I` and `Box<I>`, but that didn’t compile for two reasons:

* To make the trait object-safe, generic methods (e.g. that take a closure parameter) have a `where Self: Sized` bound. But e.g. `Box<I>: Sized` does not imply `I: Sized`, and adding an additional bound in the impl is not allowed. Some for of specialization would be needed here.
* With e.g. a `F: FnMut(Self::Item) -> bool` bound and a `type Item = I::Item` associated types, I got errors like `F does not implement FnMut(I::Item) -> bool`. This looks like a limitation in the trait resolution system not recognizing that `Self::Item == I::Item` or "propagating" that fact to `FnMut` bounds.

0 files changed, 0 insertions, 0 deletions