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rust-itertools
Feature request: into_group_btreemap
A BTreeMap version of the into_group* function group would be a nice addition.
The idea is that sometimes working with Hash is not feasible or even impossible, e.g. when you have to work with float-based datatypes as key or you would like to group your data by some custom criteria without wrapping the type and implementing custom Hash.
The into_group_btreemap() and into_group_btreemap_by() functions should work similarly how into_group_map() and into_group_btreemap_by() work, but would require K: Ord + Eq instead of K: Hash + Eq and would return BTreeMap<K, Vec<V>> instead of HashMap<K, Vec<V>>.
I have the code patched into my codebase, so I can also start a PR is this feature is required.
Hi, nice idea. It appears there is a certain need for this, as the request for other containers comes up (in different flavors) from time to time:
- https://github.com/rust-itertools/itertools/pull/276
- https://github.com/rust-itertools/itertools/issues/322
- https://github.com/rust-itertools/itertools/issues/462
- https://github.com/rust-itertools/itertools/pull/515#discussion_r556991629
- https://github.com/rust-itertools/itertools/issues/588
I'd like to put on the record (see https://github.com/rust-itertools/itertools/issues/462#issuecomment-659545723) that imho in an ideal world we would solve this problem by abstracting over the kind of the container -- leading to uniform support for HashMaps, BTreeMaps, sorted Vecs, EnumMap<Enum, Option<_>>, and possibly more, instead of having sporadic support for some of them.
It might not be easily doable, but I am unsure if duplicating functions here and there is better than exploring the possibilities of the aforementioned abstraction.
I did not see any update related to it. The only recent thing is me adding the label "generic-container". Personally, I tried some approaches to have more generic containers but nothing satisfying yet (by far).
