Enum im::hashmap::Entry [−][src]
pub enum Entry<'a, K, V, S> where
K: 'a + Hash + Eq + Clone,
V: 'a + Clone,
S: 'a + BuildHasher, { Occupied(OccupiedEntry<'a, K, V, S>), Vacant(VacantEntry<'a, K, V, S>), }
A handle for a key and its associated value.
Performance Note
When using an Entry
, the key is only ever hashed once, when you
create the Entry
. Operations on an Entry
will never trigger a
rehash, where eg. a contains_key(key)
followed by an
insert(key, default_value)
(the equivalent of
Entry::or_insert()
) would need to hash the key once for the
contains_key
and again for the insert
. The operations
generally perform similarly otherwise.
Variants
Occupied(OccupiedEntry<'a, K, V, S>)
Vacant(VacantEntry<'a, K, V, S>)
Methods
impl<'a, K, V, S> Entry<'a, K, V, S> where
K: 'a + Hash + Eq + Clone,
V: 'a + Clone,
S: 'a + BuildHasher,
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impl<'a, K, V, S> Entry<'a, K, V, S> where
K: 'a + Hash + Eq + Clone,
V: 'a + Clone,
S: 'a + BuildHasher,
pub fn or_insert(self, default: V) -> &'a mut V
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pub fn or_insert(self, default: V) -> &'a mut V
Insert the default value provided if there was no value already, and return a mutable reference to the value.
pub fn or_insert_with<F>(self, default: F) -> &'a mut V where
F: FnOnce() -> V,
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pub fn or_insert_with<F>(self, default: F) -> &'a mut V where
F: FnOnce() -> V,
Insert the default value from the provided function if there was no value already, and return a mutable reference to the value.
pub fn or_default(self) -> &'a mut V where
V: Default,
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pub fn or_default(self) -> &'a mut V where
V: Default,
Insert a default value if there was no value already, and return a mutable reference to the value.
pub fn key(&self) -> &K
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pub fn key(&self) -> &K
Get the key for this entry.
pub fn and_modify<F>(self, f: F) -> Self where
F: FnOnce(&mut V),
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pub fn and_modify<F>(self, f: F) -> Self where
F: FnOnce(&mut V),
Call the provided function to modify the value if the value exists.