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entry API

HashMap's way to insert-or-update a key in one lookup.

map.entry(key) returns an Entry for an occupied or vacant slot; or_insert, or_insert_with, and and_modify update or fill it with a single hash lookup.

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Examples

  • *tally.entry(drink).or_insert(0) += 1; counts each drink with one lookup, starting a new key at 0.

See also

HashMap Option BTreeMap
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