Struct gcollections::wrappers::btree_set::BTreeSet

pub struct BTreeSet<T> { /* fields omitted */ }

Implementations

impl<T: Ord> BTreeSet<T>

pub fn wrap(ts: StdBTreeSet<T>) -> BTreeSet<T>

Methods from Deref<Target = StdBTreeSet<T>>

pub fn range<K, R>(&self, range: R) -> Range<'_, T> where
    R: RangeBounds<K>,
    T: Borrow<K> + Ord,
    K: Ord + ?Sized, 

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.

Examples

use std::collections::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 difference(&'a self, other: &'a BTreeSet<T>) -> Difference<'a, T> where
    T: Ord, 

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

Examples

use std::collections::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 self,
    other: &'a BTreeSet<T>
) -> SymmetricDifference<'a, T> where
    T: Ord, 

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.

Examples

use std::collections::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 intersection(&'a self, other: &'a BTreeSet<T>) -> Intersection<'a, T> where
    T: Ord, 

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

Examples

use std::collections::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 union(&'a self, other: &'a BTreeSet<T>) -> Union<'a, T> where
    T: Ord, 

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

Examples

use std::collections::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 clear(&mut self)

Clears the set, removing all values.

Examples

use std::collections::BTreeSet;

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

pub fn contains<Q>(&self, value: &Q) -> bool where
    T: Borrow<Q> + Ord,
    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.

Examples

use std::collections::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> + Ord,
    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.

Examples

use std::collections::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 is_disjoint(&self, other: &BTreeSet<T>) -> bool where
    T: Ord, 

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

Examples

use std::collections::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(&self, other: &BTreeSet<T>) -> bool where
    T: Ord, 

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

Examples

use std::collections::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(&self, other: &BTreeSet<T>) -> bool where
    T: Ord, 

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

Examples

use std::collections::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> where
    T: Ord, 

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

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

Examples

Basic usage:

#![feature(map_first_last)]
use std::collections::BTreeSet;

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

pub fn last(&self) -> Option<&T> where
    T: Ord, 

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

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

Examples

Basic usage:

#![feature(map_first_last)]
use std::collections::BTreeSet;

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

pub fn pop_first(&mut self) -> Option<T> where
    T: Ord, 

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

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

Examples

#![feature(map_first_last)]
use std::collections::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> where
    T: Ord, 

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

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

Examples

#![feature(map_first_last)]
use std::collections::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 insert(&mut self, value: 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.

Examples

use std::collections::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 replace(&mut self, value: T) -> Option<T> where
    T: Ord, 

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

Examples

use std::collections::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 remove<Q>(&mut self, value: &Q) -> bool where
    T: Borrow<Q> + Ord,
    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.

Examples

use std::collections::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> + Ord,
    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 std::collections::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 retain<F>(&mut self, f: F) where
    T: Ord,
    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. The elements are visited in ascending order.

Examples

use std::collections::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 BTreeSet<T>) where
    T: Ord, 

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

Examples

use std::collections::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 split_off<Q>(&mut self, value: &Q) -> BTreeSet<T> where
    T: Borrow<Q> + Ord,
    Q: Ord + ?Sized, 

Splits the collection into two at the given value. Returns everything after the given value, including the value.

Examples

Basic usage:

use std::collections::BTreeSet;

let mut a = BTreeSet::new();
a.insert(1);
a.insert(2);
a.insert(3);
a.insert(17);
a.insert(41);

let b = a.split_off(&3);

assert_eq!(a.len(), 2);
assert_eq!(b.len(), 3);

assert!(a.contains(&1));
assert!(a.contains(&2));

assert!(b.contains(&3));
assert!(b.contains(&17));
assert!(b.contains(&41));

pub fn drain_filter<'a, F>(&'a mut self, pred: F) -> DrainFilter<'a, T, F> where
    T: Ord,
    F: 'a + FnMut(&T) -> bool, 

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

Creates an iterator that visits all values in ascending order and uses a closure to determine if a value should be removed.

If the closure returns true, the value is removed from the set and yielded. If the closure returns false, or panics, the value remains in the set and will not be yielded.

If the iterator is only partially consumed or not consumed at all, each of the remaining values is still 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.

Examples

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

#![feature(btree_drain_filter)]
use std::collections::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]);

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

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

Examples

use std::collections::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 std::collections::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);

pub fn len(&self) -> usize

Returns the number of elements in the set.

Examples

use std::collections::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.

Examples

use std::collections::BTreeSet;

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

Trait Implementations

impl<T> Collection for BTreeSet<T>

type Item = T

impl<T: Ord> Contains for BTreeSet<T>

fn contains(&self, value: &T) -> bool

impl<T> Deref for BTreeSet<T>

type Target = StdBTreeSet<T>

The resulting type after dereferencing.

fn deref<'a>(&'a self) -> &'a StdBTreeSet<T>

Dereferences the value.

impl<T> DerefMut for BTreeSet<T>

fn deref_mut<'a>(&'a mut self) -> &'a mut StdBTreeSet<T>

Mutably dereferences the value.

impl<T> Difference<BTreeSet<T>> for BTreeSet<T> where
    T: Ord + Clone, 

type Output = BTreeSet<T>

fn difference(&self, other: &BTreeSet<T>) -> BTreeSet<T>

impl<T> Intersection<BTreeSet<T>> for BTreeSet<T> where
    T: Ord + Clone, 

type Output = BTreeSet<T>

fn intersection(&self, other: &BTreeSet<T>) -> BTreeSet<T>

impl<T> SymmetricDifference<BTreeSet<T>> for BTreeSet<T> where
    T: Ord + Clone, 

type Output = BTreeSet<T>

fn symmetric_difference(&self, other: &BTreeSet<T>) -> BTreeSet<T>

impl<T> Union<BTreeSet<T>> for BTreeSet<T> where
    T: Ord + Clone, 

type Output = BTreeSet<T>

fn union(&self, other: &BTreeSet<T>) -> BTreeSet<T>