- [Release announcement](https://bluss.github.io/rust/2016/09/26/itertools-0.5.0/)
- Renamed:
- `combinations` is now `tuple_combinations`
- `combinations_n` to `combinations`
- `group_by_lazy`, `chunks_lazy` to `group_by`, `chunks`
- `Unfold::new` to `unfold()`
- `RepeatCall::new` to `repeat_call()`
- `Zip::new` to `multizip`
- `PutBack::new`, `PutBackN::new` to `put_back`, `put_back_n`
- `PutBack::with_value` is now a builder setter, not a constructor
- `MultiPeek::new`, `.multipeek()` to `multipeek()`
- `format` to `format_with` and `format_default` to `format`
- `.into_rc()` to `rciter`
- `Partition` enum is now `Either`
- Module reorganization:
- All iterator structs are under `itertools::structs` but also reexported to the top level, for backwards compatibility
- All free functions are reexported at the root, `itertools::free` will be removed in the next version
- Removed:
- `ZipSlices`, use `.zip()` instead
- `.enumerate_from()`, `ZipTrusted`, due to being unstable
- `.mend_slices()`, moved to crate `odds`
- Stride, StrideMut, moved to crate `odds`
- `linspace()`, moved to crate `itertools-num`
- `.sort_by()`, use `.sorted_by()`
- `.is_empty_hint()`, use `.size_hint()`
- `.dropn()`, use `.dropping()`
- `.map_fn()`, use `.map()`
- `.slice()`, use `.take()` / `.skip()`
- helper traits in `misc`
- `new` constructors on iterator structs, use `Itertools` trait or free functions instead
- `itertools::size_hint` is now private
- Behaviour changes:
- `format` and `format_with` helpers now panic if you try to format them more than once.
- `repeat_call` is not double ended anymore
- New features:
- tuple flattening iterator is constructible with `cons_tuples`
- itertools reexports `Either` from the `either` crate. `Either<L, R>` is an iterator when `L, R` are.
- `MinMaxResult` now implements `Copy` and `Clone`
- `tuple_combinations` supports 1-4 tuples of combinations (previously just 2)