pub enum Entry<'a, K, V, S>{
Occupied(OccupiedEntry<'a, K, V, S>),
Vacant(VacantEntry<'a, K, V, S>),
}
Expand description
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>)
An entry which exists in the map.
Vacant(VacantEntry<'a, K, V, S>)
An entry which doesn’t exist in the map.
Implementations§
source§impl<'a, K, V, S> Entry<'a, K, V, S>
impl<'a, K, V, S> Entry<'a, K, V, S>
sourcepub fn or_insert(self, default: V) -> &'a mut V
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.
sourcepub fn or_insert_with<F>(self, default: F) -> &'a mut Vwhere
F: FnOnce() -> V,
pub fn or_insert_with<F>(self, default: F) -> &'a mut Vwhere
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.
sourcepub fn or_default(self) -> &'a mut Vwhere
V: Default,
pub fn or_default(self) -> &'a mut Vwhere
V: Default,
Insert a default value if there was no value already, and return a mutable reference to the value.
sourcepub fn and_modify<F>(self, f: F) -> Self
pub fn and_modify<F>(self, f: F) -> Self
Call the provided function to modify the value if the value exists.