- Removed implementation of `DoubleEndedIterator` for `ConsTuples` (#853)

- Made `MultiProduct` fused and fixed on an empty iterator (#835, #834)

- Changed `iproduct!` to return tuples for maxi one iterator too (#870)

- Changed `PutBack::put_back` to return the old value (#880)

- Removed deprecated `repeat_call, Itertools::{foreach, step, map_results, fold_results}` (#878)

- Removed `TakeWhileInclusive::new` (#912)

- Added `Itertools::{smallest_by, smallest_by_key, largest, largest_by, largest_by_key}` (#654, #885)

- Added `Itertools::tail` (#899)

- Implemented `DoubleEndedIterator` for `ProcessResults` (#910)

- Implemented `Debug` for `FormatWith` (#931)

- Added `Itertools::get` (#891)

- Deprecated `Itertools::group_by` (renamed `chunk_by`) (#866, #879)

- Deprecated `unfold` (use `std::iter::from_fn` instead) (#871)

- Optimized `GroupingMapBy` (#873, #876)

- Relaxed `Fn` bounds to `FnMut` in `diff_with, Itertools::into_group_map_by` (#886)

- Relaxed `Debug/Clone` bounds for `MapInto` (#889)

- Documented the `use_alloc` feature (#887)

- Optimized `Itertools::set_from` (#888)

- Removed badges in `README.md` (#890)

- Added "no-std" categories in `Cargo.toml` (#894)

- Fixed `Itertools::k_smallest` on short unfused iterators (#900)

- Deprecated `Itertools::tree_fold1` (renamed `tree_reduce`) (#895)

- Deprecated `GroupingMap::fold_first` (renamed `reduce`) (#902)

- Fixed `Itertools::k_smallest(0)` to consume the iterator, optimized `Itertools::k_smallest(1)` (#909)

- Specialized `Combinations::nth` (#914)

- Specialized `MergeBy::fold` (#920)

- Specialized `CombinationsWithReplacement::nth` (#923)

- Specialized `FlattenOk::{fold, rfold}` (#927)

- Specialized `Powerset::nth` (#924)

- Documentation fixes (#882, #936)

- Fixed `assert_equal` for iterators longer than `i32::MAX` (#932)

- Updated the `must_use` message of non-lazy `KMergeBy` and `TupleCombinations` (#939)

- Tested iterator laziness (#792)

- Created `CONTRIBUTING.md` (#767)