Struct slotmap_fork_otter::SparseSecondaryMap [−][src]
pub struct SparseSecondaryMap<K: Key, V, S: BuildHasher = RandomState> { /* fields omitted */ }
Sparse secondary map, associate data with previously stored elements in a slot map.
A SparseSecondaryMap
allows you to efficiently store additional
information for each element in a slot map. You can have multiple secondary
maps per slot map, but not multiple slot maps per secondary map. It is safe
but unspecified behavior if you use keys from multiple different slot maps
in the same SparseSecondaryMap
.
A SparseSecondaryMap
does not leak memory even if you never remove
elements. In return, when you remove a key from the primary slot map, after
any insert the space associated with the removed element may be reclaimed.
Don’t expect the values associated with a removed key to stick around after
an insertion has happened!
Unlike SecondaryMap
, the SparseSecondaryMap
is backed by a
HashMap
. This means its access times are higher, but it uses less memory
and iterates faster if there are only a few elements of the slot map in the
secondary map. If most or all of the elements in a slot map are also found
in the secondary map, use a SecondaryMap
instead.
The current implementation of SparseSecondaryMap
requires std
and is
thus not available in no_std
environments.
Example usage:
let mut players = SlotMap::new(); let mut health = SparseSecondaryMap::new(); let mut ammo = SparseSecondaryMap::new(); let alice = players.insert("alice"); let bob = players.insert("bob"); for p in players.keys() { health.insert(p, 100); ammo.insert(p, 30); } // Alice attacks Bob with all her ammo! health[bob] -= ammo[alice] * 3; ammo[alice] = 0;
Implementations
impl<K: Key, V> SparseSecondaryMap<K, V, RandomState>
[src]
pub fn new() -> Self
[src]
Constructs a new, empty SparseSecondaryMap
.
Examples
let mut sec: SparseSecondaryMap<DefaultKey, i32> = SparseSecondaryMap::new();
pub fn with_capacity(capacity: usize) -> Self
[src]
Creates an empty SparseSecondaryMap
with the given capacity of slots.
The secondary map will not reallocate until it holds at least capacity
slots.
Examples
let mut sm: SlotMap<_, i32> = SlotMap::with_capacity(10); let mut sec: SparseSecondaryMap<DefaultKey, i32> = SparseSecondaryMap::with_capacity(sm.capacity());
impl<K: Key, V, S: BuildHasher> SparseSecondaryMap<K, V, S>
[src]
pub fn with_hasher(hash_builder: S) -> Self
[src]
Creates an empty SparseSecondaryMap
which will use the given hash
builder to hash keys.
The secondary map will not reallocate until it holds at least capacity
slots.
Examples
let mut sm: SlotMap<_, i32> = SlotMap::with_capacity(10); let mut sec: SparseSecondaryMap<DefaultKey, i32, _> = SparseSecondaryMap::with_hasher(RandomState::new());
pub fn with_capacity_and_hasher(capacity: usize, hash_builder: S) -> Self
[src]
Creates an empty SparseSecondaryMap
with the given capacity of slots,
using hash_builder
to hash the keys.
The secondary map will not reallocate until it holds at least capacity
slots.
Examples
let mut sm: SlotMap<_, i32> = SlotMap::with_capacity(10); let mut sec: SparseSecondaryMap<DefaultKey, i32, _> = SparseSecondaryMap::with_capacity_and_hasher(10, RandomState::new());
pub fn len(&self) -> usize
[src]
Returns the number of elements in the secondary map.
Examples
let mut sm = SlotMap::new(); let k = sm.insert(4); let mut squared = SparseSecondaryMap::new(); assert_eq!(squared.len(), 0); squared.insert(k, 16); assert_eq!(squared.len(), 1);
pub fn is_empty(&self) -> bool
[src]
Returns if the secondary map is empty.
Examples
let mut sec: SparseSecondaryMap<DefaultKey, i32> = SparseSecondaryMap::new(); assert!(sec.is_empty());
pub fn capacity(&self) -> usize
[src]
Returns the number of elements the SparseSecondaryMap
can hold without
reallocating.
Examples
let mut sec: SparseSecondaryMap<DefaultKey, i32> = SparseSecondaryMap::with_capacity(10); assert!(sec.capacity() >= 10);
pub fn reserve(&mut self, additional: usize)
[src]
Reserves capacity for at least additional
more slots in the
SparseSecondaryMap
. The collection may reserve more space to avoid
frequent reallocations.
Panics
Panics if the new allocation size overflows usize
.
Examples
let mut sec: SparseSecondaryMap<DefaultKey, i32> = SparseSecondaryMap::new(); sec.reserve(10); assert!(sec.capacity() >= 10);
pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError>
[src]
unstable
only.Tries to reserve capacity for at least additional
more slots in the
SparseSecondaryMap
. The collection may reserve more space to avoid
frequent reallocations.
Examples
let mut sec: SparseSecondaryMap<DefaultKey, i32> = SparseSecondaryMap::new(); sec.try_reserve(10).unwrap(); assert!(sec.capacity() >= 10);
pub fn contains_key(&self, key: K) -> bool
[src]
Returns true
if the secondary map contains key
.
Examples
let mut sm = SlotMap::new(); let k = sm.insert(4); let mut squared = SparseSecondaryMap::new(); assert!(!squared.contains_key(k)); squared.insert(k, 16); assert!(squared.contains_key(k));
pub fn insert(&mut self, key: K, value: V) -> Option<V>
[src]
Inserts a value into the secondary map at the given key
. Can silently
fail if key
was removed from the originating slot map.
Returns None
if this key was not present in the map, the old value
otherwise.
Examples
let mut sm = SlotMap::new(); let k = sm.insert(4); let mut squared = SparseSecondaryMap::new(); assert_eq!(squared.insert(k, 0), None); assert_eq!(squared.insert(k, 4), Some(0)); // You don't have to use insert if the key is already in the secondary map. squared[k] *= squared[k]; assert_eq!(squared[k], 16);
pub fn remove(&mut self, key: K) -> Option<V>
[src]
Removes a key from the secondary map, returning the value at the key if
the key was not previously removed. If key
was removed from the
originating slot map, its corresponding entry in the secondary map may
or may not already be removed.
Examples
let mut sm = SlotMap::new(); let mut squared = SparseSecondaryMap::new(); let k = sm.insert(4); squared.insert(k, 16); squared.remove(k); assert!(!squared.contains_key(k)); // It's not necessary to remove keys deleted from the primary slot map, they // get deleted automatically when their slots are reused on a subsequent insert. squared.insert(k, 16); sm.remove(k); // Remove k from the slot map, making an empty slot. let new_k = sm.insert(2); // Since sm only has one empty slot, this reuses it. assert!(!squared.contains_key(new_k)); // Space reuse does not mean equal keys. assert!(squared.contains_key(k)); // Slot has not been reused in squared yet. squared.insert(new_k, 4); assert!(!squared.contains_key(k)); // Old key is no longer available.
pub fn retain<F>(&mut self, f: F) where
F: FnMut(K, &mut V) -> bool,
[src]
F: FnMut(K, &mut V) -> bool,
Retains only the elements specified by the predicate.
In other words, remove all key-value pairs (k, v)
such that
f(k, &mut v)
returns false. This method invalidates any removed keys.
Examples
let mut sm = SlotMap::new(); let mut sec = SparseSecondaryMap::new(); let k1 = sm.insert(0); sec.insert(k1, 10); let k2 = sm.insert(1); sec.insert(k2, 11); let k3 = sm.insert(2); sec.insert(k3, 12); sec.retain(|key, val| key == k1 || *val == 11); assert!(sec.contains_key(k1)); assert!(sec.contains_key(k2)); assert!(!sec.contains_key(k3)); assert_eq!(2, sec.len());
pub fn clear(&mut self)
[src]
Clears the secondary map. Keeps the allocated memory for reuse.
Examples
let mut sm = SlotMap::new(); let mut sec = SparseSecondaryMap::new(); for i in 0..10 { sec.insert(sm.insert(i), i); } assert_eq!(sec.len(), 10); sec.clear(); assert_eq!(sec.len(), 0);
pub fn drain(&mut self) -> Drain<'_, K, V>ⓘ
[src]
Clears the slot map, returning all key-value pairs in arbitrary order as an iterator. Keeps the allocated memory for reuse.
When the iterator is dropped all elements in the slot map are removed,
even if the iterator was not fully consumed. If the iterator is not
dropped (using e.g. std::mem::forget
), only the elements that were
iterated over are removed.
Examples
let mut sm = SlotMap::new(); let k = sm.insert(0); let mut sec = SparseSecondaryMap::new(); sec.insert(k, 1); let v: Vec<_> = sec.drain().collect(); assert_eq!(sec.len(), 0); assert_eq!(v, vec![(k, 1)]);
pub fn get(&self, key: K) -> Option<&V>
[src]
Returns a reference to the value corresponding to the key.
Examples
let mut sm = SlotMap::new(); let key = sm.insert("foo"); let mut sec = SparseSecondaryMap::new(); sec.insert(key, "bar"); assert_eq!(sec.get(key), Some(&"bar")); sec.remove(key); assert_eq!(sec.get(key), None);
pub fn get_mut(&mut self, key: K) -> Option<&mut V>
[src]
Returns a mutable reference to the value corresponding to the key.
Examples
let mut sm = SlotMap::new(); let key = sm.insert("test"); let mut sec = SparseSecondaryMap::new(); sec.insert(key, 3.5); if let Some(x) = sec.get_mut(key) { *x += 3.0; } assert_eq!(sec[key], 6.5);
pub fn get_disjoint_mut<const N: usize>(
&mut self,
keys: [K; N]
) -> Option<[&mut V; N]>
[src]
&mut self,
keys: [K; N]
) -> Option<[&mut V; N]>
unstable
only.Returns mutable references to the values corresponding to the given keys. All keys must be valid and disjoint, otherwise None is returned.
Examples
let mut sm = SlotMap::new(); let mut sec = SparseSecondaryMap::new(); let ka = sm.insert(()); sec.insert(ka, "butter"); let kb = sm.insert(()); sec.insert(kb, "apples"); let kc = sm.insert(()); sec.insert(kc, "charlie"); sec.remove(kc); // Make key c invalid. assert_eq!(sec.get_disjoint_mut([ka, kb, kc]), None); // Has invalid key. assert_eq!(sec.get_disjoint_mut([ka, ka]), None); // Not disjoint. let [a, b] = sec.get_disjoint_mut([ka, kb]).unwrap(); std::mem::swap(a, b); assert_eq!(sec[ka], "apples"); assert_eq!(sec[kb], "butter");
pub fn iter(&self) -> Iter<'_, K, V>ⓘ
[src]
An iterator visiting all key-value pairs in arbitrary order. The
iterator element type is (K, &'a V)
.
This function must iterate over all slots, empty or not. In the face of many deleted elements it can be inefficient.
Examples
let mut sm = SlotMap::new(); let mut sec = SparseSecondaryMap::new(); let k0 = sm.insert(0); sec.insert(k0, 10); let k1 = sm.insert(1); sec.insert(k1, 11); let k2 = sm.insert(2); sec.insert(k2, 12); for (k, v) in sec.iter() { println!("key: {:?}, val: {}", k, v); }
pub fn iter_mut(&mut self) -> IterMut<'_, K, V>ⓘ
[src]
An iterator visiting all key-value pairs in arbitrary order, with
mutable references to the values. The iterator element type is
(K, &'a mut V)
.
This function must iterate over all slots, empty or not. In the face of many deleted elements it can be inefficient.
Examples
let mut sm = SlotMap::new(); let mut sec = SparseSecondaryMap::new(); let k0 = sm.insert(1); sec.insert(k0, 10); let k1 = sm.insert(2); sec.insert(k1, 20); let k2 = sm.insert(3); sec.insert(k2, 30); for (k, v) in sec.iter_mut() { if k != k1 { *v *= -1; } } assert_eq!(sec[k0], -10); assert_eq!(sec[k1], 20); assert_eq!(sec[k2], -30);
pub fn keys(&self) -> Keys<'_, K, V>ⓘ
[src]
An iterator visiting all keys in arbitrary order. The iterator element
type is K
.
This function must iterate over all slots, empty or not. In the face of many deleted elements it can be inefficient.
Examples
let mut sm = SlotMap::new(); let mut sec = SparseSecondaryMap::new(); let k0 = sm.insert(1); sec.insert(k0, 10); let k1 = sm.insert(2); sec.insert(k1, 20); let k2 = sm.insert(3); sec.insert(k2, 30); let keys: HashSet<_> = sec.keys().collect(); let check: HashSet<_> = vec![k0, k1, k2].into_iter().collect(); assert_eq!(keys, check);
pub fn values(&self) -> Values<'_, K, V>ⓘ
[src]
An iterator visiting all values in arbitrary order. The iterator element
type is &'a V
.
This function must iterate over all slots, empty or not. In the face of many deleted elements it can be inefficient.
Examples
let mut sm = SlotMap::new(); let mut sec = SparseSecondaryMap::new(); let k0 = sm.insert(1); sec.insert(k0, 10); let k1 = sm.insert(2); sec.insert(k1, 20); let k2 = sm.insert(3); sec.insert(k2, 30); let values: HashSet<_> = sec.values().collect(); let check: HashSet<_> = vec![&10, &20, &30].into_iter().collect(); assert_eq!(values, check);
pub fn values_mut(&mut self) -> ValuesMut<'_, K, V>ⓘ
[src]
An iterator visiting all values mutably in arbitrary order. The iterator
element type is &'a mut V
.
This function must iterate over all slots, empty or not. In the face of many deleted elements it can be inefficient.
Examples
let mut sm = SlotMap::new(); let mut sec = SparseSecondaryMap::new(); sec.insert(sm.insert(1), 10); sec.insert(sm.insert(2), 20); sec.insert(sm.insert(3), 30); sec.values_mut().for_each(|n| { *n *= 3 }); let values: HashSet<_> = sec.into_iter().map(|(_k, v)| v).collect(); let check: HashSet<_> = vec![30, 60, 90].into_iter().collect(); assert_eq!(values, check);
pub fn entry(&mut self, key: K) -> Option<Entry<'_, K, V>>
[src]
Gets the given key’s corresponding Entry
in the map for in-place
manipulation. May return None
if the key was removed from the
originating slot map.
Examples
let mut sm = SlotMap::new(); let mut sec = SparseSecondaryMap::new(); let k = sm.insert(1); let v = sec.entry(k).unwrap().or_insert(10); assert_eq!(*v, 10);
Trait Implementations
impl<K: Clone + Key, V: Clone, S: Clone + BuildHasher> Clone for SparseSecondaryMap<K, V, S>
[src]
fn clone(&self) -> SparseSecondaryMap<K, V, S>
[src]
pub fn clone_from(&mut self, source: &Self)
1.0.0[src]
impl<K: Debug + Key, V: Debug, S: Debug + BuildHasher> Debug for SparseSecondaryMap<K, V, S>
[src]
impl<K, V, S> Default for SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher + Default,
[src]
K: Key,
S: BuildHasher + Default,
impl<K, V, S> Eq for SparseSecondaryMap<K, V, S> where
K: Key,
V: Eq,
S: BuildHasher,
[src]
K: Key,
V: Eq,
S: BuildHasher,
impl<'a, K, V, S> Extend<(K, &'a V)> for SparseSecondaryMap<K, V, S> where
K: Key,
V: 'a + Copy,
S: BuildHasher,
[src]
K: Key,
V: 'a + Copy,
S: BuildHasher,
fn extend<I: IntoIterator<Item = (K, &'a V)>>(&mut self, iter: I)
[src]
pub fn extend_one(&mut self, item: A)
[src]
pub fn extend_reserve(&mut self, additional: usize)
[src]
impl<K, V, S> Extend<(K, V)> for SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]
K: Key,
S: BuildHasher,
fn extend<I: IntoIterator<Item = (K, V)>>(&mut self, iter: I)
[src]
pub fn extend_one(&mut self, item: A)
[src]
pub fn extend_reserve(&mut self, additional: usize)
[src]
impl<K, V, S> FromIterator<(K, V)> for SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher + Default,
[src]
K: Key,
S: BuildHasher + Default,
fn from_iter<I: IntoIterator<Item = (K, V)>>(iter: I) -> Self
[src]
impl<K, V, S> Index<K> for SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]
K: Key,
S: BuildHasher,
impl<K, V, S> IndexMut<K> for SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]
K: Key,
S: BuildHasher,
impl<'a, K, V, S> IntoIterator for &'a SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]
K: Key,
S: BuildHasher,
type Item = (K, &'a V)
The type of the elements being iterated over.
type IntoIter = Iter<'a, K, V>
Which kind of iterator are we turning this into?
fn into_iter(self) -> Self::IntoIter
[src]
impl<'a, K, V, S> IntoIterator for &'a mut SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]
K: Key,
S: BuildHasher,
type Item = (K, &'a mut V)
The type of the elements being iterated over.
type IntoIter = IterMut<'a, K, V>
Which kind of iterator are we turning this into?
fn into_iter(self) -> Self::IntoIter
[src]
impl<K, V, S> IntoIterator for SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]
K: Key,
S: BuildHasher,
type Item = (K, V)
The type of the elements being iterated over.
type IntoIter = IntoIter<K, V>
Which kind of iterator are we turning this into?
fn into_iter(self) -> Self::IntoIter
[src]
impl<K, V, S> PartialEq<SparseSecondaryMap<K, V, S>> for SparseSecondaryMap<K, V, S> where
K: Key,
V: PartialEq,
S: BuildHasher,
[src]
K: Key,
V: PartialEq,
S: BuildHasher,
Auto Trait Implementations
impl<K, V, S> RefUnwindSafe for SparseSecondaryMap<K, V, S> where
S: RefUnwindSafe,
V: RefUnwindSafe,
S: RefUnwindSafe,
V: RefUnwindSafe,
impl<K, V, S> Send for SparseSecondaryMap<K, V, S> where
S: Send,
V: Send,
S: Send,
V: Send,
impl<K, V, S> Sync for SparseSecondaryMap<K, V, S> where
S: Sync,
V: Sync,
S: Sync,
V: Sync,
impl<K, V, S> Unpin for SparseSecondaryMap<K, V, S> where
S: Unpin,
V: Unpin,
S: Unpin,
V: Unpin,
impl<K, V, S> UnwindSafe for SparseSecondaryMap<K, V, S> where
S: UnwindSafe,
V: UnwindSafe,
S: UnwindSafe,
V: UnwindSafe,
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
[src]
T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
[src]
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]
T: ?Sized,
pub fn borrow_mut(&mut self) -> &mut T
[src]
impl<T> From<T> for T
[src]
impl<T, U> Into<U> for T where
U: From<T>,
[src]
U: From<T>,
impl<T> ToOwned for T where
T: Clone,
[src]
T: Clone,
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
[src]
pub fn clone_into(&self, target: &mut T)
[src]
impl<T, U> TryFrom<U> for T where
U: Into<T>,
[src]
U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
[src]
impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
[src]
U: TryFrom<T>,