Use the bucket API from hashbrown v0.16.1 #424
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This lets us simplify `OccupiedEntry` to just a reference and a bucket index, rather than needing a separate reference to our `Vec` while the inner entry holds a reference to the `HashTable`. This in turn lets us get rid of the `RefMut` abstraction that was providing common methods for that pair of references. The `OccupiedEntry` currently holds the index for the vector as well, but this is more of an optimization since most entry methods need it, so we don't have to indirectly read it through the bucket each time. Thus the overall size hasn't changed, but we could drop that if we decided the size was more important. The sizes of `VacantEntry` and `IndexedEntry` *are* reduced though, because they're also now holding a single map reference rather than the double `RefMut`, which was only needed before due the structure of the `OccupiedEntry`. The overall `Entry` should also be smaller as a result.
cuviper
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This is similar to indexmap-rs/indexmap#424, simplify a lot of code by using a bucket index in `OccupiedEntry` rather than having to split references. The effects are a little more pronounced here because our `RefMut` needed **3** references, due to the extra offset tracking, so with that gone, now *every* `*Entry` type is reduced in size.
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This lets us simplify
OccupiedEntryto just a reference and a bucketindex, rather than needing a separate reference to our
Vecwhile theinner entry holds a reference to the
HashTable. This in turn lets usget rid of the
RefMutabstraction that was providing common methodsfor that pair of references.
The
OccupiedEntrycurrently holds the index for the vector as well,but this is more of an optimization since most entry methods need it, so
we don't have to indirectly read it through the bucket each time. Thus
the overall size hasn't changed, but we could drop that if we decided
the size was more important.
The sizes of
VacantEntryandIndexedEntryare reduced though,because they're also now holding a single map reference rather than the
double
RefMut, which was only needed before due the structure of theOccupiedEntry. The overallEntryshould also be smaller as a result.