Given the following code: ``` impl<T: ?Sized, Idx> IndexRanges<Idx> for T where T: Index<Range<Idx>, Output = Self::Output> + Index<RangeTo<Idx>, Output = Self::Output> + Index<RangeFrom<Idx>, Output = Self::Output> + Index<RangeInclusive<Idx>, Output = Self::Output> + Index<RangeToInclusive<Idx>, Output = Self::Output> + Index<RangeFull>, { } ``` rustfmt moves the `where` onto the same line as the `impl`. However, if you put a `fn func() {}` inside, it won't. This may need to wait for a style edition to fix.