Struct im::hashmap::HashMap

pub struct HashMap<K, V, S = RandomState> { /* fields omitted */ }

A hash map.

An immutable hash map using hash array mapped tries.

Most operations on this map are O(log_x n) for a suitably high x that it should be nearly O(1) for most maps. Because of this, it's a great choice for a generic map as long as you don't mind that keys will need to implement Hash and Eq.

Map entries will have a predictable order based on the hasher being used. Unless otherwise specified, all maps will share an instance of the default RandomState hasher, which will produce consistent hashes for the duration of its lifetime, but not between restarts of your program.

Methods

impl<K, V> HashMap<K, V, RandomState> where
    K: Hash + Eq, 

pub fn new() -> Self

Construct an empty hash map.

pub fn singleton<RK, RV>(k: RK, v: RV) -> HashMap<K, V> where
    RK: Shared<K>,
    RV: Shared<V>, 

Construct a hash map with a single mapping.

Examples

let map = HashMap::singleton(123, "onetwothree");
assert_eq!(
  map.get(&123),
  Some(Arc::new("onetwothree"))
);

impl<K, V, S> HashMap<K, V, S>

pub fn is_empty(&self) -> bool

Test whether a hash map is empty.

Time: O(1)

Examples

assert!(
  !hashmap!{1 => 2}.is_empty()
);
assert!(
  HashMap::<i32, i32>::new().is_empty()
);

pub fn len(&self) -> usize

Get the size of a hash map.

Time: O(1)

Examples

assert_eq!(3, hashmap!{
  1 => 11,
  2 => 22,
  3 => 33
}.len());

impl<K, V, S> HashMap<K, V, S> where
    K: Hash + Eq,
    S: BuildHasher, 

pub fn with_hasher<RS>(hasher: RS) -> Self where
    RS: Shared<S>, 

Construct an empty hash map using the provided hasher.

pub fn new_from<K1, V1>(&self) -> HashMap<K1, V1, S> where
    K1: Hash + Eq, 

Construct an empty hash map using the same hasher as the current hash map.

pub fn iter(&self) -> Iter<(Arc<K>, Arc<V>)>

Get an iterator over the key/value pairs of a hash map.

Please note that the order is consistent between maps using the same hasher, but no other ordering guarantee is offered. Items will not come out in insertion order or sort order. They will, however, come out in the same order every time for the same map.

Important traits for Keys<K, V>

impl<K, V> Iterator for Keys<K, V> type Item = Arc<K>;

pub fn keys(&self) -> Keys<K, V>

Get an iterator over a hash map's keys.

Please note that the order is consistent between maps using the same hasher, but no other ordering guarantee is offered. Items will not come out in insertion order or sort order. They will, however, come out in the same order every time for the same map.

Important traits for Values<K, V>

impl<K, V> Iterator for Values<K, V> type Item = Arc<V>;

pub fn values(&self) -> Values<K, V>

Get an iterator over a hash map's values.

Please note that the order is consistent between maps using the same hasher, but no other ordering guarantee is offered. Items will not come out in insertion order or sort order. They will, however, come out in the same order every time for the same map.

pub fn get<BK: ?Sized>(&self, k: &BK) -> Option<Arc<V>> where
    BK: Hash + Eq,
    K: Borrow<BK>, 

Get the value for a key from a hash map.

Time: O(log n)

Examples

let map = hashmap!{123 => "lol"};
assert_eq!(
  map.get(&123),
  Some(Arc::new("lol"))
);

pub fn get_or<BK: ?Sized, RV>(&self, k: &BK, default: RV) -> Arc<V> where
    BK: Hash + Eq,
    K: Borrow<BK>,
    RV: Shared<V>, 

Get the value for a key from a hash map, or a default value if the key isn't in the map.

Time: O(log n)

Examples

let map = hashmap!{123 => "lol"};
assert_eq!(
  map.get_or(&123, "hi"),
  Arc::new("lol")
);
assert_eq!(
  map.get_or(&321, "hi"),
  Arc::new("hi")
);

pub fn contains_key<BK: ?Sized>(&self, k: &BK) -> bool where
    BK: Hash + Eq,
    K: Borrow<BK>, 

Test for the presence of a key in a hash map.

Time: O(log n)

Examples

let map = hashmap!{123 => "lol"};
assert!(
  map.contains_key(&123)
);
assert!(
  !map.contains_key(&321)
);

pub fn insert<RK, RV>(&self, k: RK, v: RV) -> Self where
    RK: Shared<K>,
    RV: Shared<V>, 

Construct a new hash map by inserting a key/value mapping into a map.

If the map already has a mapping for the given key, the previous value is overwritten.

Time: O(log n)

Examples

let map = hashmap!{};
assert_eq!(
  map.insert(123, "123"),
  hashmap!{123 => "123"}
);

pub fn insert_mut<RK, RV>(&mut self, k: RK, v: RV) where
    RK: Shared<K>,
    RV: Shared<V>, 

Insert a key/value mapping into a map.

If the map already has a mapping for the given key, the previous value is overwritten.

This is a copy-on-write operation, so that the parts of the set's structure which are shared with other sets will be safely copied before mutating.

Time: O(log n)

Examples

let mut map = hashmap!{};
map.insert_mut(123, "123");
map.insert_mut(456, "456");
assert_eq!(
  map,
  hashmap!{123 => "123", 456 => "456"}
);

pub fn set<RK, RV>(&self, k: RK, v: RV) -> Self where
    RK: Shared<K>,
    RV: Shared<V>, 

Construct a new map by inserting a key/value mapping into a map.

This is an alias for insert.

Time: O(log n)

pub fn set_mut<RK, RV>(&mut self, k: RK, v: RV) where
    RK: Shared<K>,
    RV: Shared<V>, 

Insert a key/value mapping into a map, mutating it in place when it is safe to do so.

This is an alias for insert_mut.

Time: O(log n)

pub fn insert_with<RK, RV, F>(self, k: RK, v: RV, f: F) -> Self where
    RK: Shared<K>,
    RV: Shared<V>,
    F: FnOnce(Arc<V>, Arc<V>) -> Arc<V>, 

Construct a new hash map by inserting a key/value mapping into a map.

If the map already has a mapping for the given key, we call the provided function with the old value and the new value, and insert the result as the new value.

Time: O(log n)

pub fn insert_with_key<RK, RV, F>(self, k: RK, v: RV, f: F) -> Self where
    F: FnOnce(Arc<K>, Arc<V>, Arc<V>) -> Arc<V>,
    RK: Shared<K>,
    RV: Shared<V>, 

Construct a new map by inserting a key/value mapping into a map.

If the map already has a mapping for the given key, we call the provided function with the key, the old value and the new value, and insert the result as the new value.

Time: O(log n)

pub fn insert_lookup_with_key<RK, RV, F>(
    self,
    k: RK,
    v: RV,
    f: F
) -> (Option<Arc<V>>, Self) where
    F: FnOnce(Arc<K>, Arc<V>, Arc<V>) -> Arc<V>,
    RK: Shared<K>,
    RV: Shared<V>, 

Construct a new map by inserting a key/value mapping into a map, returning the old value for the key as well as the new map.

If the map already has a mapping for the given key, we call the provided function with the key, the old value and the new value, and insert the result as the new value.

Time: O(log n)

pub fn update<BK: ?Sized, F>(&self, k: &BK, f: F) -> Self where
    BK: Hash + Eq,
    K: Borrow<BK>,
    F: FnOnce(Arc<V>) -> Option<Arc<V>>, 

Update the value for a given key by calling a function with the current value and overwriting it with the function's return value.

Time: O(log n)

pub fn update_with_key<BK: ?Sized, F>(&self, k: &BK, f: F) -> Self where
    BK: Hash + Eq,
    K: Borrow<BK>,
    F: FnOnce(Arc<K>, Arc<V>) -> Option<Arc<V>>, 

Update the value for a given key by calling a function with the key and the current value and overwriting it with the function's return value.

Time: O(log n)

pub fn update_lookup_with_key<BK: ?Sized, F>(
    &self,
    k: &BK,
    f: F
) -> (Option<Arc<V>>, Self) where
    BK: Hash + Eq,
    K: Borrow<BK>,
    F: FnOnce(Arc<K>, Arc<V>) -> Option<Arc<V>>, 

Update the value for a given key by calling a function with the key and the current value and overwriting it with the function's return value.

If the key was not in the map, the function is never called and the map is left unchanged.

Return a tuple of the old value, if there was one, and the new map.

Time: O(log n)

pub fn alter<RK, F>(&self, f: F, k: RK) -> Self where
    F: FnOnce(Option<Arc<V>>) -> Option<Arc<V>>,
    RK: Shared<K>, 

Update the value for a given key by calling a function with the current value and overwriting it with the function's return value.

This is like the update method, except with more control: the function gets an Option<V> and returns the same, so that it can decide to delete a mapping instead of updating the value, and decide what to do if the key isn't in the map.

Time: O(log n)

pub fn remove<BK: ?Sized>(&self, k: &BK) -> Self where
    BK: Hash + Eq,
    K: Borrow<BK>, 

Remove a key/value pair from a hash map, if it exists.

Time: O(log n)

pub fn remove_mut<BK: ?Sized>(&mut self, k: &BK) where
    BK: Hash + Eq,
    K: Borrow<BK>, 

Remove a key/value mapping from a map if it exists.

This is a copy-on-write operation, so that the parts of the set's structure which are shared with other sets will be safely copied before mutating.

Time: O(log n)

Examples

let mut map = hashmap!{123 => "123", 456 => "456"};
map.remove_mut(&123);
map.remove_mut(&456);
assert!(map.is_empty());

pub fn pop<BK: ?Sized>(&self, k: &BK) -> Option<(Arc<V>, Self)> where
    BK: Hash + Eq,
    K: Borrow<BK>, 

Remove a key/value pair from a map, if it exists, and return the removed value as well as the updated list.

Time: O(log n)

pub fn pop_mut<BK: ?Sized>(&mut self, k: &BK) -> Option<Arc<V>> where
    BK: Hash + Eq,
    K: Borrow<BK>, 

Remove a key/value pair from a map, if it exists, and return the removed value.

This is a copy-on-write operation, so that the parts of the set's structure which are shared with other sets will be safely copied before mutating.

Time: O(log n)

pub fn pop_with_key<BK: ?Sized>(&self, k: &BK) -> Option<(Arc<K>, Arc<V>, Self)> where
    BK: Hash + Eq,
    K: Borrow<BK>, 

Remove a key/value pair from a map, if it exists, and return the removed key and value as well as the updated list.

Time: O(log n)

pub fn pop_with_key_mut<BK: ?Sized>(
    &mut self,
    k: &BK
) -> Option<(Arc<K>, Arc<V>)> where
    BK: Hash + Eq,
    K: Borrow<BK>, 

Remove a key/value pair from a map, if it exists, and return the removed key and value.

This is a copy-on-write operation, so that the parts of the set's structure which are shared with other sets will be safely copied before mutating.

Time: O(log n)

pub fn union<RM>(&self, other: RM) -> Self where
    RM: Borrow<Self>, 

Construct the union of two maps, keeping the values in the current map when keys exist in both maps.

pub fn union_with<F, RM>(&self, other: RM, f: F) -> Self where
    F: Fn(Arc<V>, Arc<V>) -> Arc<V>,
    RM: Borrow<Self>, 

Construct the union of two maps, using a function to decide what to do with the value when a key is in both maps.

pub fn union_with_key<F, RM>(&self, other: RM, f: F) -> Self where
    F: Fn(Arc<K>, Arc<V>, Arc<V>) -> Arc<V>,
    RM: Borrow<Self>, 

Construct the union of two maps, using a function to decide what to do with the value when a key is in both maps. The function receives the key as well as both values.

pub fn unions<I>(i: I) -> Self where
    S: Default,
    I: IntoIterator<Item = Self>, 

Construct the union of a sequence of maps, selecting the value of the leftmost when a key appears in more than one map.

pub fn unions_with<I, F>(i: I, f: F) -> Self where
    S: Default,
    I: IntoIterator<Item = Self>,
    F: Fn(Arc<V>, Arc<V>) -> Arc<V>, 

Construct the union of a sequence of maps, using a function to decide what to do with the value when a key is in more than one map.

pub fn unions_with_key<I, F>(i: I, f: F) -> Self where
    S: Default,
    I: IntoIterator<Item = Self>,
    F: Fn(Arc<K>, Arc<V>, Arc<V>) -> Arc<V>, 

Construct the union of a sequence of maps, using a function to decide what to do with the value when a key is in more than one map. The function receives the key as well as both values.

pub fn difference<B, RM>(&self, other: RM) -> Self where
    RM: Borrow<HashMap<K, B, S>>, 

Construct the difference between two maps by discarding keys which occur in both maps.

pub fn difference_with<B, RM, F>(&self, other: RM, f: F) -> Self where
    F: Fn(Arc<V>, Arc<B>) -> Option<Arc<V>>,
    RM: Borrow<HashMap<K, B, S>>, 

Construct the difference between two maps by using a function to decide what to do if a key occurs in both.

pub fn difference_with_key<B, RM, F>(&self, other: RM, f: F) -> Self where
    F: Fn(Arc<K>, Arc<V>, Arc<B>) -> Option<Arc<V>>,
    RM: Borrow<HashMap<K, B, S>>, 

Construct the difference between two maps by using a function to decide what to do if a key occurs in both. The function receives the key as well as both values.

pub fn intersection<B, RM>(&self, other: RM) -> Self where
    RM: Borrow<HashMap<K, B, S>>, 

Construct the intersection of two maps, keeping the values from the current map.

pub fn intersection_with<B, C, RM, F>(
    &self,
    other: RM,
    f: F
) -> HashMap<K, C, S> where
    F: Fn(Arc<V>, Arc<B>) -> Arc<C>,
    RM: Borrow<HashMap<K, B, S>>, 

Construct the intersection of two maps, calling a function with both values for each key and using the result as the value for the key.

pub fn intersection_with_key<B, C, RM, F>(
    &self,
    other: RM,
    f: F
) -> HashMap<K, C, S> where
    F: Fn(Arc<K>, Arc<V>, Arc<B>) -> Arc<C>,
    RM: Borrow<HashMap<K, B, S>>, 

Construct the intersection of two maps, calling a function with the key and both values for each key and using the result as the value for the key.

pub fn merge_with_key<B, C, RM, FC, F1, F2>(
    &self,
    other: RM,
    combine: FC,
    only1: F1,
    only2: F2
) -> HashMap<K, C, S> where
    RM: Borrow<HashMap<K, B, S>>,
    FC: Fn(Arc<K>, Arc<V>, Arc<B>) -> Option<Arc<C>>,
    F1: FnOnce(Self) -> HashMap<K, C, S>,
    F2: FnOnce(HashMap<K, B, S>) -> HashMap<K, C, S>, 

Merge two maps.

First, we call the combine function for each key/value pair which exists in both maps, updating the value or discarding it according to the function's return value.

The only1 and only2 functions are called with the key/value pairs which are only in the first and the second list respectively. The results of these are then merged with the result of the first operation.

pub fn is_submap_by<B, RM, F>(&self, other: RM, cmp: F) -> bool where
    F: Fn(Arc<V>, Arc<B>) -> bool,
    RM: Borrow<HashMap<K, B, S>>, 

Test whether a map is a submap of another map, meaning that all keys in our map must also be in the other map, with the same values.

Use the provided function to decide whether values are equal.

pub fn is_proper_submap_by<B, RM, F>(&self, other: RM, cmp: F) -> bool where
    F: Fn(Arc<V>, Arc<B>) -> bool,
    RM: Borrow<HashMap<K, B, S>>, 

Test whether a map is a proper submap of another map, meaning that all keys in our map must also be in the other map, with the same values. To be a proper submap, ours must also contain fewer keys than the other map.

Use the provided function to decide whether values are equal.

pub fn is_submap<RM>(&self, other: RM) -> bool where
    V: PartialEq,
    RM: Borrow<Self>, 

Test whether a map is a submap of another map, meaning that all keys in our map must also be in the other map, with the same values.

pub fn is_proper_submap<RM>(&self, other: RM) -> bool where
    V: PartialEq,
    RM: Borrow<Self>, 

Test whether a map is a proper submap of another map, meaning that all keys in our map must also be in the other map, with the same values. To be a proper submap, ours must also contain fewer keys than the other map.

Trait Implementations

impl<K: Ord + Hash + Eq, V, S: BuildHasher> From<HashMap<K, V, S>> for OrdMap<K, V>

fn from(m: HashMap<K, V, S>) -> Self

Performs the conversion.

impl<'a, K: Ord + Hash + Eq, V, S: BuildHasher> From<&'a HashMap<K, V, S>> for OrdMap<K, V>

fn from(m: &'a HashMap<K, V, S>) -> Self

Performs the conversion.

impl<K, V, S> Clone for HashMap<K, V, S>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<K, V, S> PartialEq for HashMap<K, V, S> where
    K: Hash + Eq,
    V: PartialEq,
    S: BuildHasher, 

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<K: Hash + Eq, V: Eq, S: BuildHasher> Eq for HashMap<K, V, S>

impl<K, V, S> PartialOrd for HashMap<K, V, S> where
    K: Hash + Eq + PartialOrd,
    V: PartialOrd,
    S: BuildHasher, 

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<K, V, S> Ord for HashMap<K, V, S> where
    K: Hash + Eq + Ord,
    V: Ord,
    S: BuildHasher, 

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl<K, V, S> Hash for HashMap<K, V, S> where
    K: Hash + Eq,
    V: Hash,
    S: BuildHasher, 

fn hash<H>(&self, state: &mut H) where
    H: Hasher, 

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl<K, V, S> Default for HashMap<K, V, S> where
    K: Hash + Eq,
    S: BuildHasher + Default, 

fn default() -> Self

Returns the "default value" for a type.

impl<K, V, S> Add for HashMap<K, V, S> where
    K: Hash + Eq,
    S: BuildHasher, 

type Output = HashMap<K, V, S>

The resulting type after applying the + operator.

fn add(self, other: Self) -> Self::Output

Performs the + operation.

impl<'a, K, V, S> Add for &'a HashMap<K, V, S> where
    K: Hash + Eq,
    S: BuildHasher, 

type Output = HashMap<K, V, S>

The resulting type after applying the + operator.

fn add(self, other: Self) -> Self::Output

Performs the + operation.

impl<K, V, S> Sum for HashMap<K, V, S> where
    K: Hash + Eq,
    S: BuildHasher + Default, 

fn sum<I>(it: I) -> Self where
    I: Iterator<Item = Self>, 

Method which takes an iterator and generates Self from the elements by "summing up" the items.

impl<K, V, S, RK, RV> Extend<(RK, RV)> for HashMap<K, V, S> where
    K: Hash + Eq,
    S: BuildHasher,
    RK: Shared<K>,
    RV: Shared<V>, 

fn extend<I>(&mut self, iter: I) where
    I: IntoIterator<Item = (RK, RV)>, 

Extends a collection with the contents of an iterator.

impl<'a, BK: ?Sized, K, V, S> Index<&'a BK> for HashMap<K, V, S> where
    BK: Hash + Eq,
    K: Hash + Eq + Borrow<BK>,
    S: BuildHasher, 

type Output = V

The returned type after indexing.

fn index(&self, key: &BK) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<'a, BK: ?Sized, K, V, S> IndexMut<&'a BK> for HashMap<K, V, S> where
    BK: Hash + Eq,
    K: Hash + Eq + Borrow<BK>,
    V: Clone,
    S: BuildHasher, 

fn index_mut(&mut self, key: &BK) -> &mut Self::Output

Performs the mutable indexing (container[index]) operation.

impl<K, V, S> Debug for HashMap<K, V, S> where
    K: Hash + Eq + Debug,
    V: Debug,
    S: BuildHasher, 

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl<'a, K, V, S> IntoIterator for &'a HashMap<K, V, S> where
    K: Hash + Eq,
    S: BuildHasher, 

type Item = (Arc<K>, Arc<V>)

The type of the elements being iterated over.

type IntoIter = Iter<(Arc<K>, Arc<V>)>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<K, V, S> IntoIterator for HashMap<K, V, S> where
    K: Hash + Eq,
    S: BuildHasher, 

type Item = (Arc<K>, Arc<V>)

The type of the elements being iterated over.

type IntoIter = Iter<(Arc<K>, Arc<V>)>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<K, V, RK, RV, S> FromIterator<(RK, RV)> for HashMap<K, V, S> where
    K: Hash + Eq,
    RK: Shared<K>,
    RV: Shared<V>,
    S: BuildHasher + Default, 

fn from_iter<T>(i: T) -> Self where
    T: IntoIterator<Item = (RK, RV)>, 

Creates a value from an iterator.

impl<K, V, S> AsRef<HashMap<K, V, S>> for HashMap<K, V, S>

fn as_ref(&self) -> &Self

Performs the conversion.

impl<'m, 'k, 'v, K: ?Sized, V: ?Sized, OK, OV, SA, SB> From<&'m HashMap<&'k K, &'v V, SA>> for HashMap<OK, OV, SB> where
    K: Hash + Eq + ToOwned<Owned = OK>,
    V: ToOwned<Owned = OV>,
    OK: Hash + Eq + Borrow<K>,
    OV: Borrow<V>,
    SA: BuildHasher,
    SB: BuildHasher + Default, 

fn from(m: &HashMap<&K, &V, SA>) -> Self

Performs the conversion.

impl<'a, K: Hash + Eq, V: Clone, RK, RV, S> From<&'a [(RK, RV)]> for HashMap<K, V, S> where
    &'a RK: Shared<K>,
    &'a RV: Shared<V>,
    S: BuildHasher + Default, 

fn from(m: &'a [(RK, RV)]) -> Self

Performs the conversion.

impl<K: Hash + Eq, V, RK, RV, S> From<Vec<(RK, RV)>> for HashMap<K, V, S> where
    RK: Shared<K>,
    RV: Shared<V>,
    S: BuildHasher + Default, 

fn from(m: Vec<(RK, RV)>) -> Self

Performs the conversion.

impl<'a, K: Hash + Eq, V, RK, RV, S> From<&'a Vec<(RK, RV)>> for HashMap<K, V, S> where
    &'a RK: Shared<K>,
    &'a RV: Shared<V>,
    S: BuildHasher + Default, 

fn from(m: &'a Vec<(RK, RV)>) -> Self

Performs the conversion.

impl<K: Hash + Eq, V, RK: Hash + Eq, RV, S> From<HashMap<RK, RV>> for HashMap<K, V, S> where
    RK: Shared<K>,
    RV: Shared<V>,
    S: BuildHasher + Default, 

fn from(m: HashMap<RK, RV>) -> Self

Performs the conversion.

impl<'a, K: Hash + Eq, V, RK: Hash + Eq, RV, S> From<&'a HashMap<RK, RV>> for HashMap<K, V, S> where
    &'a RK: Shared<K>,
    &'a RV: Shared<V>,
    S: BuildHasher + Default, 

fn from(m: &'a HashMap<RK, RV>) -> Self

Performs the conversion.

impl<K: Hash + Eq, V, RK, RV, S> From<BTreeMap<RK, RV>> for HashMap<K, V, S> where
    RK: Shared<K>,
    RV: Shared<V>,
    S: BuildHasher + Default, 

fn from(m: BTreeMap<RK, RV>) -> Self

Performs the conversion.

impl<'a, K: Hash + Eq, V, RK, RV, S> From<&'a BTreeMap<RK, RV>> for HashMap<K, V, S> where
    &'a RK: Shared<K>,
    &'a RV: Shared<V>,
    S: BuildHasher + Default, 

fn from(m: &'a BTreeMap<RK, RV>) -> Self

Performs the conversion.