Struct BTreeSet 

pub struct BTreeSet<T, C> { /* private fields */ }

A set based on a B-Tree.

See BTreeMap’s documentation for a detailed discussion of this collection’s performance benefits and drawbacks.

It is a logic error for an item to be modified in such a way that the item’s ordering relative to any other item, as determined by the Ord trait, changes while it is in the set. This is normally only possible through Cell, RefCell, global state, I/O, or unsafe code.

Implementations

impl<T, C> BTreeSet<T, C>

pub fn new() -> Self

where C: Default,

Makes a new, empty BTreeSet.

Example

use btree_slab::BTreeSet;

let mut set: BTreeSet<i32> = BTreeSet::new();

pub fn len(&self) -> usize

Returns the number of elements in the set.

Example

use btree_slab::BTreeSet;

let mut v = BTreeSet::new();
assert_eq!(v.len(), 0);
v.insert(1);
assert_eq!(v.len(), 1);

pub fn is_empty(&self) -> bool

Returns true if the set contains no elements.

Example

use btree_slab::BTreeSet;

let mut v = BTreeSet::new();
assert!(v.is_empty());
v.insert(1);
assert!(!v.is_empty());

impl<T, C> BTreeSet<T, C>

where C: SimpleCollectionRef + Slab<Node<T, ()>>,

pub fn iter(&self) -> Iter<'_, T, C>

Gets an iterator that visits the values in the BTreeSet in ascending order.

Examples

use btree_slab::BTreeSet;

let set: BTreeSet<usize> = [1, 2, 3].iter().cloned().collect();
let mut set_iter = set.iter();
assert_eq!(set_iter.next(), Some(&1));
assert_eq!(set_iter.next(), Some(&2));
assert_eq!(set_iter.next(), Some(&3));
assert_eq!(set_iter.next(), None);

Values returned by the iterator are returned in ascending order:

use btree_slab::BTreeSet;

let set: BTreeSet<usize> = [3, 1, 2].iter().cloned().collect();
let mut set_iter = set.iter();
assert_eq!(set_iter.next(), Some(&1));
assert_eq!(set_iter.next(), Some(&2));
assert_eq!(set_iter.next(), Some(&3));
assert_eq!(set_iter.next(), None);

impl<T: Ord, C> BTreeSet<T, C>

where C: SimpleCollectionRef + Slab<Node<T, ()>>,

pub fn contains<Q>(&self, value: &Q) -> bool

where T: Borrow<Q>, Q: Ord + ?Sized,

Returns true if the set contains a value.

The value may be any borrowed form of the set’s value type, but the ordering on the borrowed form must match the ordering on the value type.

Example

use btree_slab::BTreeSet;

let set: BTreeSet<_> = [1, 2, 3].iter().cloned().collect();
assert_eq!(set.contains(&1), true);
assert_eq!(set.contains(&4), false);

pub fn get<Q>(&self, value: &Q) -> Option<&T>

where T: Borrow<Q>, Q: Ord + ?Sized,

Returns a reference to the value in the set, if any, that is equal to the given value.

The value may be any borrowed form of the set’s value type, but the ordering on the borrowed form must match the ordering on the value type.

Example

use btree_slab::BTreeSet;

let set: BTreeSet<_> = [1, 2, 3].iter().cloned().collect();
assert_eq!(set.get(&2), Some(&2));
assert_eq!(set.get(&4), None);

pub fn range<K, R>(&self, range: R) -> Range<'_, T, C>

where K: Ord + ?Sized, T: Borrow<K>, R: RangeBounds<K>,

Constructs a double-ended iterator over a sub-range of elements in the set. The simplest way is to use the range syntax min..max, thus range(min..max) will yield elements from min (inclusive) to max (exclusive). The range may also be entered as (Bound<T>, Bound<T>), so for example range((Excluded(4), Included(10))) will yield a left-exclusive, right-inclusive range from 4 to 10.

Example

use btree_slab::BTreeSet;
use std::ops::Bound::Included;

let mut set = BTreeSet::new();
set.insert(3);
set.insert(5);
set.insert(8);
for &elem in set.range((Included(&4), Included(&8))) {
    println!("{}", elem);
}
assert_eq!(Some(&5), set.range(4..).next());

pub fn union<'a, D>(&'a self, other: &'a BTreeSet<T, D>) -> Union<'a, T, C, D>

where D: SimpleCollectionRef + Slab<Node<T, ()>>,

Visits the values representing the union, i.e., all the values in self or other, without duplicates, in ascending order.

Example

use btree_slab::BTreeSet;

let mut a = BTreeSet::new();
a.insert(1);

let mut b = BTreeSet::new();
b.insert(2);

let union: Vec<_> = a.union(&b).cloned().collect();
assert_eq!(union, [1, 2]);

pub fn intersection<'a, D>( &'a self, other: &'a BTreeSet<T, D>, ) -> Intersection<'a, T, C, D>

where D: SimpleCollectionRef + Slab<Node<T, ()>>,

Visits the values representing the intersection, i.e., the values that are both in self and other, in ascending order.

Example

use btree_slab::BTreeSet;

let mut a = BTreeSet::new();
a.insert(1);
a.insert(2);

let mut b = BTreeSet::new();
b.insert(2);
b.insert(3);

let intersection: Vec<_> = a.intersection(&b).cloned().collect();
assert_eq!(intersection, [2]);

pub fn difference<'a, D>( &'a self, other: &'a BTreeSet<T, D>, ) -> Difference<'a, T, C, D>

where D: SimpleCollectionRef + Slab<Node<T, ()>>,

Visits the values representing the difference, i.e., the values that are in self but not in other, in ascending order.

Example

use btree_slab::BTreeSet;

let mut a = BTreeSet::new();
a.insert(1);
a.insert(2);

let mut b = BTreeSet::new();
b.insert(2);
b.insert(3);

let diff: Vec<_> = a.difference(&b).cloned().collect();
assert_eq!(diff, [1]);

pub fn symmetric_difference<'a, D>( &'a self, other: &'a BTreeSet<T, D>, ) -> SymmetricDifference<'a, T, C, D>

where D: SimpleCollectionRef + Slab<Node<T, ()>>,

Visits the values representing the symmetric difference, i.e., the values that are in self or in other but not in both, in ascending order.

Example

use btree_slab::BTreeSet;

let mut a = BTreeSet::new();
a.insert(1);
a.insert(2);

let mut b = BTreeSet::new();
b.insert(2);
b.insert(3);

let sym_diff: Vec<_> = a.symmetric_difference(&b).cloned().collect();
assert_eq!(sym_diff, [1, 3]);

pub fn is_disjoint<D>(&self, other: &BTreeSet<T, D>) -> bool

where D: SimpleCollectionRef + Slab<Node<T, ()>>,

Returns true if self has no elements in common with other. This is equivalent to checking for an empty intersection.

Example

use btree_slab::BTreeSet;

let a: BTreeSet<_> = [1, 2, 3].iter().cloned().collect();
let mut b = BTreeSet::new();

assert_eq!(a.is_disjoint(&b), true);
b.insert(4);
assert_eq!(a.is_disjoint(&b), true);
b.insert(1);
assert_eq!(a.is_disjoint(&b), false);

pub fn is_subset<D>(&self, other: &BTreeSet<T, D>) -> bool

where D: SimpleCollectionRef + Slab<Node<T, ()>>,

Returns true if the set is a subset of another, i.e., other contains at least all the values in self.

Example

use btree_slab::BTreeSet;

let sup: BTreeSet<_> = [1, 2, 3].iter().cloned().collect();
let mut set = BTreeSet::new();

assert_eq!(set.is_subset(&sup), true);
set.insert(2);
assert_eq!(set.is_subset(&sup), true);
set.insert(4);
assert_eq!(set.is_subset(&sup), false);

pub fn is_superset<D>(&self, other: &BTreeSet<T, D>) -> bool

where D: SimpleCollectionRef + Slab<Node<T, ()>>,

Returns true if the set is a superset of another, i.e., self contains at least all the values in other.

Example

use btree_slab::BTreeSet;

let sub: BTreeSet<_> = [1, 2].iter().cloned().collect();
let mut set = BTreeSet::new();

assert_eq!(set.is_superset(&sub), false);

set.insert(0);
set.insert(1);
assert_eq!(set.is_superset(&sub), false);

set.insert(2);
assert_eq!(set.is_superset(&sub), true);

pub fn first(&self) -> Option<&T>

Returns a reference to the first value in the set, if any. This value is always the minimum of all values in the set.

Example

use btree_slab::BTreeSet;

let mut map = BTreeSet::new();
assert_eq!(map.first(), None);
map.insert(1);
assert_eq!(map.first(), Some(&1));
map.insert(2);
assert_eq!(map.first(), Some(&1));

pub fn last(&self) -> Option<&T>

Returns a reference to the last value in the set, if any. This value is always the maximum of all values in the set.

Example

use btree_slab::BTreeSet;

let mut map = BTreeSet::new();
assert_eq!(map.first(), None);
map.insert(1);
assert_eq!(map.last(), Some(&1));
map.insert(2);
assert_eq!(map.last(), Some(&2));

impl<T: Ord, C> BTreeSet<T, C>

where C: SimpleCollectionRef + SimpleCollectionMut + SlabMut<Node<T, ()>>,

pub fn clear(&mut self)

where C: Clear,

Clears the set, removing all values.

Examples

use btree_slab::BTreeSet;

let mut v = BTreeSet::new();
v.insert(1);
v.clear();
assert!(v.is_empty());

pub fn insert(&mut self, element: T) -> bool

where T: Ord,

Adds a value to the set.

If the set did not have this value present, true is returned.

If the set did have this value present, false is returned, and the entry is not updated. See the module-level documentation for more.

Example

use btree_slab::BTreeSet;

let mut set = BTreeSet::new();

assert_eq!(set.insert(2), true);
assert_eq!(set.insert(2), false);
assert_eq!(set.len(), 1);

pub fn remove<Q>(&mut self, value: &Q) -> bool

where T: Borrow<Q>, Q: Ord + ?Sized,

Removes a value from the set. Returns whether the value was present in the set.

The value may be any borrowed form of the set’s value type, but the ordering on the borrowed form must match the ordering on the value type.

Example

use btree_slab::BTreeSet;

let mut set = BTreeSet::new();

set.insert(2);
assert_eq!(set.remove(&2), true);
assert_eq!(set.remove(&2), false);

pub fn take<Q>(&mut self, value: &Q) -> Option<T>

where T: Borrow<Q>, Q: Ord + ?Sized,

Removes and returns the value in the set, if any, that is equal to the given one.

The value may be any borrowed form of the set’s value type, but the ordering on the borrowed form must match the ordering on the value type.

Examples

use btree_slab::BTreeSet;

let mut set: BTreeSet<_> = [1, 2, 3].iter().cloned().collect();
assert_eq!(set.take(&2), Some(2));
assert_eq!(set.take(&2), None);

pub fn replace(&mut self, value: T) -> Option<T>

Adds a value to the set, replacing the existing value, if any, that is equal to the given one. Returns the replaced value.

Example

use btree_slab::BTreeSet;

let mut set = BTreeSet::new();
set.insert(Vec::<i32>::new());

assert_eq!(set.get(&[][..]).unwrap().capacity(), 0);
set.replace(Vec::with_capacity(10));
assert_eq!(set.get(&[][..]).unwrap().capacity(), 10);

pub fn pop_first(&mut self) -> Option<T>

Removes the first value from the set and returns it, if any. The first value is always the minimum value in the set.

Example

use btree_slab::BTreeSet;

let mut set = BTreeSet::new();

set.insert(1);
while let Some(n) = set.pop_first() {
    assert_eq!(n, 1);
}
assert!(set.is_empty());

pub fn pop_last(&mut self) -> Option<T>

Removes the last value from the set and returns it, if any. The last value is always the maximum value in the set.

Example

use btree_slab::BTreeSet;

let mut set = BTreeSet::new();

set.insert(1);
while let Some(n) = set.pop_last() {
    assert_eq!(n, 1);
}
assert!(set.is_empty());

pub fn retain<F>(&mut self, f: F)

where F: FnMut(&T) -> bool,

Retains only the elements specified by the predicate.

In other words, remove all elements e such that f(&e) returns false.

Example

use btree_slab::BTreeSet;

let xs = [1, 2, 3, 4, 5, 6];
let mut set: BTreeSet<i32> = xs.iter().cloned().collect();
// Keep only the even numbers.
set.retain(|&k| k % 2 == 0);
assert!(set.iter().eq([2, 4, 6].iter()));

pub fn append(&mut self, other: &mut Self)

where C: Default,

Moves all elements from other into Self, leaving other empty.

Example

use btree_slab::BTreeSet;

let mut a = BTreeSet::new();
a.insert(1);
a.insert(2);
a.insert(3);

let mut b = BTreeSet::new();
b.insert(3);
b.insert(4);
b.insert(5);

a.append(&mut b);

assert_eq!(a.len(), 5);
assert_eq!(b.len(), 0);

assert!(a.contains(&1));
assert!(a.contains(&2));
assert!(a.contains(&3));
assert!(a.contains(&4));
assert!(a.contains(&5));

pub fn drain_filter<'a, F>(&'a mut self, pred: F) -> DrainFilter<'a, T, C, F>

where F: 'a + FnMut(&T) -> bool,

Creates an iterator which uses a closure to determine if a value should be removed.

If the closure returns true, then the value is removed and yielded. If the closure returns false, the value will remain in the list and will not be yielded by the iterator.

If the iterator is only partially consumed or not consumed at all, each of the remaining values will still be subjected to the closure and removed and dropped if it returns true.

It is unspecified how many more values will be subjected to the closure if a panic occurs in the closure, or if a panic occurs while dropping a value, or if the DrainFilter itself is leaked.

Example

Splitting a set into even and odd values, reusing the original set:

use btree_slab::BTreeSet;

let mut set: BTreeSet<i32> = (0..8).collect();
let evens: BTreeSet<_> = set.drain_filter(|v| v % 2 == 0).collect();
let odds = set;
assert_eq!(evens.into_iter().collect::<Vec<_>>(), vec![0, 2, 4, 6]);
assert_eq!(odds.into_iter().collect::<Vec<_>>(), vec![1, 3, 5, 7]);

Trait Implementations

impl<T: Clone, C: Clone> Clone for BTreeSet<T, C>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T, C: Default> Default for BTreeSet<T, C>

fn default() -> Self

Returns the “default value” for a type.

impl<'a, T: 'a + Ord + Copy, C> Extend<&'a T> for BTreeSet<T, C>

where C: SimpleCollectionRef + SimpleCollectionMut + SlabMut<Node<T, ()>>,

fn extend<I>(&mut self, iter: I)

where I: IntoIterator<Item = &'a T>,

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl<T: Ord, C> Extend<T> for BTreeSet<T, C>

where C: SimpleCollectionRef + SimpleCollectionMut + SlabMut<Node<T, ()>>,

fn extend<I>(&mut self, iter: I)

where I: IntoIterator<Item = T>,

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl<T: Ord, C> FromIterator<T> for BTreeSet<T, C>

where C: SimpleCollectionRef + SimpleCollectionMut + SlabMut<Node<T, ()>> + Default,

fn from_iter<I>(iter: I) -> Self

where I: IntoIterator<Item = T>,

Creates a value from an iterator.

impl<T: Hash, C> Hash for BTreeSet<T, C>

where C: SimpleCollectionRef + Slab<Node<T, ()>>,

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

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'a, T, C> IntoIterator for &'a BTreeSet<T, C>

where C: SimpleCollectionRef + SlabMut<Node<T, ()>>,

type Item = &'a T

The type of the elements being iterated over.

type IntoIter = Iter<'a, T, C>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Iter<'a, T, C>

Creates an iterator from a value.

impl<T, C> IntoIterator for BTreeSet<T, C>

where C: SimpleCollectionRef + SimpleCollectionMut + SlabMut<Node<T, ()>>,

type Item = T

The type of the elements being iterated over.

type IntoIter = IntoIter<T, C>

Which kind of iterator are we turning this into?

fn into_iter(self) -> IntoIter<T, C>

Creates an iterator from a value.

impl<T: Ord, C> Ord for BTreeSet<T, C>

where C: SimpleCollectionRef + Slab<Node<T, ()>>,

fn cmp(&self, other: &BTreeSet<T, C>) -> Ordering

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T, L: PartialEq<T>, C, D> PartialEq<BTreeSet<L, D>> for BTreeSet<T, C>

where C: SimpleCollectionRef + Slab<Node<T, ()>>, D: SimpleCollectionRef + Slab<Node<L, ()>>,

fn eq(&self, other: &BTreeSet<L, D>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T, L: PartialOrd<T>, C, D> PartialOrd<BTreeSet<L, D>> for BTreeSet<T, C>

where C: SimpleCollectionRef + Slab<Node<T, ()>>, D: SimpleCollectionRef + Slab<Node<L, ()>>,

fn partial_cmp(&self, other: &BTreeSet<L, D>) -> Option<Ordering>

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl<T: Eq, C> Eq for BTreeSet<T, C>

where C: SimpleCollectionRef + Slab<Node<T, ()>>,