Josh Stone 974bc455ee Specialize flattening iterators with only one inner item ... For iterators like `Once` and `option::IntoIter` that only ever have a single item at most, the front and back iterator states in `FlatMap` and `Flatten` are a waste, as they're always consumed already. We can use specialization for these types to simplify the iterator methods. It's a somewhat common pattern to use `flatten()` for options and results, even recommended by [multiple][1] [clippy][2] [lints][3]. The implementation is more efficient with `filter_map`, as mentioned in [clippy#9377], but this new specialization should close some of that gap for existing code that flattens. [1]: https://rust-lang.github.io/rust-clippy/master/#filter_map_identity [2]: https://rust-lang.github.io/rust-clippy/master/#option_filter_map [3]: https://rust-lang.github.io/rust-clippy/master/#result_filter_map [clippy#9377]: https://github.com/rust-lang/rust-clippy/issues/9377		2024-02-16 13:49:29 -08:00
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adapters	Specialize flattening iterators with only one inner item	2024-02-16 13:49:29 -08:00
traits	Replace NonZero::<_>::new with NonZero::new.	2024-02-15 08:09:42 +01:00
mod.rs	remove redundant imports	2023-12-10 10:56:22 +08:00
range.rs	Replace NonZero::<_>::new with NonZero::new.	2024-02-15 08:09:42 +01:00
sources.rs	VecDeque::resize should re-use the buffer in the passed-in element	2022-11-15 00:53:26 -08:00