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Struct std::collections::BTreeSet

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

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.

Examples

use std::collections::BTreeSet;

// Type inference lets us omit an explicit type signature (which
// would be `BTreeSet<&str>` in this example).
let mut books = BTreeSet::new();

// Add some books.
books.insert("A Dance With Dragons");
books.insert("To Kill a Mockingbird");
books.insert("The Odyssey");
books.insert("The Great Gatsby");

// Check for a specific one.
if !books.contains("The Winds of Winter") {
    println!("We have {} books, but The Winds of Winter ain't one.",
             books.len());
}

// Remove a book.
books.remove("The Odyssey");

// Iterate over everything.
for book in &books {
    println!("{}", book);
}

Methods

impl<T> BTreeSet<T> where
    T: Ord, [src]

pub fn new() -> BTreeSet<T>[src]

Makes a new BTreeSet with a reasonable choice of B.

Examples

use std::collections::BTreeSet;

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

pub fn range<K, R>(&self, range: R) -> Range<T> where
    K: Ord + ?Sized,
    R: RangeBounds<K>,
    T: Borrow<K>, [src]1.17.0

ⓘImportant traits for Range<'a, T>
impl<'a, T> Iterator for Range<'a, T>
    type Item = &'a T;

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>[src]

ⓘImportant traits for Difference<'a, T>
impl<'a, T> Iterator for Difference<'a, T> where
    T: Ord, 
    type Item = &'a T;

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>[src]

ⓘImportant traits for SymmetricDifference<'a, T>
impl<'a, T> Iterator for SymmetricDifference<'a, T> where
    T: Ord, 
    type Item = &'a 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.

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>[src]

ⓘImportant traits for Intersection<'a, T>
impl<'a, T> Iterator for Intersection<'a, T> where
    T: Ord, 
    type Item = &'a T;

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>[src]

ⓘImportant traits for Union<'a, T>
impl<'a, T> Iterator for Union<'a, T> where
    T: Ord, 
    type Item = &'a T;

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)[src]

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
    Q: Ord + ?Sized,
    T: Borrow<Q>, [src]

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
    Q: Ord + ?Sized,
    T: Borrow<Q>, [src]1.9.0

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[src]

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[src]

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[src]

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 insert(&mut self, value: T) -> bool[src]

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>[src]1.9.0

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
    Q: Ord + ?Sized,
    T: Borrow<Q>, [src]

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
    Q: Ord + ?Sized,
    T: Borrow<Q>, [src]1.9.0

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 append(&mut self, other: &mut BTreeSet<T>)[src]1.11.0

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, key: &Q) -> BTreeSet<T> where
    Q: Ord + ?Sized,
    T: Borrow<Q>, [src]1.11.0

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

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));

impl<T> BTreeSet<T>[src]

pub fn iter(&self) -> Iter<T>[src]

ⓘImportant traits for Iter<'a, T>
impl<'a, T> Iterator for Iter<'a, T>
    type Item = &'a 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[src]

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[src]

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> BitAnd<&'_ BTreeSet<T>> for &'_ BTreeSet<T> where
    T: Ord + Clone, [src]

type Output = BTreeSet<T>

The resulting type after applying the & operator.

fn bitand(self, rhs: &BTreeSet<T>) -> BTreeSet<T>[src]

Returns the intersection of self and rhs as a new BTreeSet<T>.

Examples

use std::collections::BTreeSet;

let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect();
let b: BTreeSet<_> = vec![2, 3, 4].into_iter().collect();

let result = &a & &b;
let result_vec: Vec<_> = result.into_iter().collect();
assert_eq!(result_vec, [2, 3]);

impl<'_, '_, T> BitOr<&'_ BTreeSet<T>> for &'_ BTreeSet<T> where
    T: Ord + Clone, [src]

type Output = BTreeSet<T>

The resulting type after applying the | operator.

fn bitor(self, rhs: &BTreeSet<T>) -> BTreeSet<T>[src]

Returns the union of self and rhs as a new BTreeSet<T>.

Examples

use std::collections::BTreeSet;

let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect();
let b: BTreeSet<_> = vec![3, 4, 5].into_iter().collect();

let result = &a | &b;
let result_vec: Vec<_> = result.into_iter().collect();
assert_eq!(result_vec, [1, 2, 3, 4, 5]);

impl<T> Hash for BTreeSet<T> where
    T: Hash, [src]

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, [src]1.3.0

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

impl<T> Eq for BTreeSet<T> where
    T: Eq, [src]

impl<'a, T> Extend<&'a T> for BTreeSet<T> where
    T: 'a + Copy + Ord, [src]1.2.0

impl<T> Extend<T> for BTreeSet<T> where
    T: Ord, [src]

impl<T> Ord for BTreeSet<T> where
    T: Ord, [src]

fn max(self, other: Self) -> Self[src]1.21.0

Compares and returns the maximum of two values. Read more

fn min(self, other: Self) -> Self[src]1.21.0

Compares and returns the minimum of two values. Read more

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

🔬 This is a nightly-only experimental API. (clamp #44095)

Restrict a value to a certain interval. Read more

impl<T> Debug for BTreeSet<T> where
    T: Debug, [src]

impl<'_, '_, T> BitXor<&'_ BTreeSet<T>> for &'_ BTreeSet<T> where
    T: Ord + Clone, [src]

type Output = BTreeSet<T>

The resulting type after applying the ^ operator.

fn bitxor(self, rhs: &BTreeSet<T>) -> BTreeSet<T>[src]

Returns the symmetric difference of self and rhs as a new BTreeSet<T>.

Examples

use std::collections::BTreeSet;

let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect();
let b: BTreeSet<_> = vec![2, 3, 4].into_iter().collect();

let result = &a ^ &b;
let result_vec: Vec<_> = result.into_iter().collect();
assert_eq!(result_vec, [1, 4]);

impl<'_, '_, T> Sub<&'_ BTreeSet<T>> for &'_ BTreeSet<T> where
    T: Ord + Clone, [src]

type Output = BTreeSet<T>

The resulting type after applying the - operator.

fn sub(self, rhs: &BTreeSet<T>) -> BTreeSet<T>[src]

Returns the difference of self and rhs as a new BTreeSet<T>.

Examples

use std::collections::BTreeSet;

let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect();
let b: BTreeSet<_> = vec![3, 4, 5].into_iter().collect();

let result = &a - &b;
let result_vec: Vec<_> = result.into_iter().collect();
assert_eq!(result_vec, [1, 2]);

impl<T> IntoIterator for BTreeSet<T>[src]

type Item = T

The type of the elements being iterated over.

type IntoIter = IntoIter<T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> IntoIter<T>[src]

ⓘImportant traits for IntoIter<T>
impl<T> Iterator for IntoIter<T>
    type Item = T;

Gets an iterator for moving out the BTreeSet's contents.

Examples

use std::collections::BTreeSet;

let set: BTreeSet<usize> = [1, 2, 3, 4].iter().cloned().collect();

let v: Vec<_> = set.into_iter().collect();
assert_eq!(v, [1, 2, 3, 4]);

impl<'a, T> IntoIterator for &'a BTreeSet<T>[src]

type Item = &'a T

The type of the elements being iterated over.

type IntoIter = Iter<'a, T>

Which kind of iterator are we turning this into?

ⓘImportant traits for Iter<'a, T>
impl<'a, T> Iterator for Iter<'a, T>
    type Item = &'a T;

impl<T> PartialEq<BTreeSet<T>> for BTreeSet<T> where
    T: PartialEq<T>, [src]

impl<T> Clone for BTreeSet<T> where
    T: Clone, [src]

fn clone_from(&mut self, source: &Self)[src]

Performs copy-assignment from source. Read more

impl<T> FromIterator<T> for BTreeSet<T> where
    T: Ord, [src]

impl<T> Default for BTreeSet<T> where
    T: Ord, [src]

fn default() -> BTreeSet<T>[src]

Makes an empty BTreeSet<T> with a reasonable choice of B.

impl<T> PartialOrd<BTreeSet<T>> for BTreeSet<T> where
    T: PartialOrd<T>, [src]

Auto Trait Implementations

impl<T> UnwindSafe for BTreeSet<T> where
    T: RefUnwindSafe + UnwindSafe, 

impl<T> RefUnwindSafe for BTreeSet<T> where
    T: RefUnwindSafe, 

impl<T> Unpin for BTreeSet<T> where
    T: Unpin, 

impl<T> Send for BTreeSet<T> where
    T: Send, 

impl<T> Sync for BTreeSet<T> where
    T: Sync, 

Blanket Implementations

impl<T, U> TryFrom<U> for T where
    U: Into<T>, [src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<I> IntoIterator for I where
    I: Iterator, [src]

type Item = <I as Iterator>::Item

The type of the elements being iterated over.

type IntoIter = I

Which kind of iterator are we turning this into?

impl<T, U> Into<U> for T where
    U: From<T>, [src]

impl<T> From<T> for T[src]

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, [src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<T> Borrow<T> for T where
    T: ?Sized, [src]

ⓘImportant traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
    F: Unpin + Future + ?Sized, 
    type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized, 
    type Item = <I as Iterator>::Item;
impl<'_, R: Read + ?Sized> Read for &'_ mut R
impl<'_, W: Write + ?Sized> Write for &'_ mut W

impl<T> BorrowMut<T> for T where
    T: ?Sized, [src]

ⓘImportant traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
    F: Unpin + Future + ?Sized, 
    type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
    I: Iterator + ?Sized, 
    type Item = <I as Iterator>::Item;
impl<'_, R: Read + ?Sized> Read for &'_ mut R
impl<'_, W: Write + ?Sized> Write for &'_ mut W

impl<T> Any for T where
    T: 'static + ?Sized, [src]

impl<T> ToOwned for T where
    T: Clone, [src]

type Owned = T

The resulting type after obtaining ownership.

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/collections/struct.BTreeSet.html