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Struct std::collections::btree_set::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]

Makes a new BTreeSet with a reasonable choice of B.

Examples

use std::collections::BTreeSet;

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

ⓘ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());

ⓘ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]);

ⓘ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]);

ⓘ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]);

ⓘ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]);

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());

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);

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);

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);

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);

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);

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);

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);

Removes a value from the set. Returns true if 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);

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);

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));

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]

ⓘ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);

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);

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

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

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

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

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

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

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

The type of the elements being iterated over.

Which kind of iterator are we turning this into?

ⓘ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]

The type of the elements being iterated over.

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;

Creates an iterator from a value. Read more

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

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

The resulting type after applying the | operator.

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

The resulting type after applying the & operator.

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

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

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

Creates a value from an iterator. Read more

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

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

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

Extends a collection with the contents of an iterator. Read more

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

Extends a collection with the contents of an iterator. Read more

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

Feeds this value into the given [Hasher]. Read more

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

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

Formats the value using the given formatter. Read more

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

The resulting type after applying the ^ operator.

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

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

This method tests for !=.

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

The resulting type after applying the - operator.

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

This method returns an Ordering between self and other. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

Auto Trait Implementations

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

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

Blanket Implementations

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

🔬 This is a nightly-only experimental API. (try_from #33417)

The type returned in the event of a conversion error.

🔬 This is a nightly-only experimental API. (try_from #33417)

Performs the conversion.

impl<T> From for T [src]

Performs the conversion.

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

The type of the elements being iterated over.

Which kind of iterator are we turning this into?

Creates an iterator from a value. Read more

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

🔬 This is a nightly-only experimental API. (try_from #33417)

The type returned in the event of a conversion error.

🔬 This is a nightly-only experimental API. (try_from #33417)

Performs the conversion.

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

Performs the conversion.

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

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

Immutably borrows from an owned value. Read more

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

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

Mutably borrows from an owned value. Read more

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

🔬 This is a nightly-only experimental API. (get_type_id #27745)this method will likely be replaced by an associated static

Gets the TypeId of self. Read more

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

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into #41263)recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

© 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/btree_set/struct.BTreeSet.html