Struct std::collections::BTreeSet

pub struct BTreeSet<T> {
    // some 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.

Methods

impl<T> BTreeSet<T> where T: Ord

fn new() -> BTreeSet<T>

Makes a new BTreeSet with a reasonable choice of B.

Examples

fn main() { #![allow(unused_mut)] use std::collections::BTreeSet; let mut set: BTreeSet<i32> = BTreeSet::new(); }

use std::collections::BTreeSet;

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

fn with_b(b: usize) -> BTreeSet<T>

Deprecated since 1.4.0

: niche API

Makes a new BTreeSet with the given B.

B cannot be less than 2.

impl<T> BTreeSet<T>

fn iter(&self) -> Iter<T>

Gets an iterator over the BTreeSet's contents.

Examples

fn main() { use std::collections::BTreeSet; let set: BTreeSet<usize> = [1, 2, 3, 4].iter().cloned().collect(); for x in set.iter() { println!("{}", x); } let v: Vec<_> = set.iter().cloned().collect(); assert_eq!(v, [1, 2, 3, 4]); }

use std::collections::BTreeSet;

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

for x in set.iter() {
    println!("{}", x);
}

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

impl<T> BTreeSet<T> where T: Ord

fn range<Min = T, Max = T>(&'a self, min: Bound<&Min>, max: Bound<&Max>) -> Range<'a, T> where Max: Ord + ?Sized, Min: Ord + ?Sized, T: Borrow<Min> + Borrow<Max>

Unstable (btree_range #27787)

: matches collection reform specification, waiting for dust to settle

Constructs a double-ended iterator over a sub-range of elements in the set, starting at min, and ending at max. If min is Unbounded, then it will be treated as "negative infinity", and if max is Unbounded, then it will be treated as "positive infinity". Thus range(Unbounded, Unbounded) will yield the whole collection.

Examples

#![feature(btree_range, collections_bound)] fn main() { use std::collections::BTreeSet; use std::collections::Bound::{Included, Unbounded}; 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(Included(&4), Unbounded).next()); }

#![feature(btree_range, collections_bound)]

use std::collections::BTreeSet;
use std::collections::Bound::{Included, Unbounded};

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(Included(&4), Unbounded).next());

impl<T> BTreeSet<T> where T: Ord

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

Visits the values representing the difference, in ascending order.

Examples

fn main() { 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]); }

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]);

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

Visits the values representing the symmetric difference, in ascending order.

Examples

fn main() { 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]); }

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]);

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

Visits the values representing the intersection, in ascending order.

Examples

fn main() { 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]); }

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]);

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

Visits the values representing the union, in ascending order.

Examples

fn main() { 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]); }

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]);

fn len(&self) -> usize

Returns the number of elements in the set.

Examples

fn main() { use std::collections::BTreeSet; let mut v = BTreeSet::new(); assert_eq!(v.len(), 0); v.insert(1); assert_eq!(v.len(), 1); }

use std::collections::BTreeSet;

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

fn is_empty(&self) -> bool

Returns true if the set contains no elements.

Examples

fn main() { use std::collections::BTreeSet; let mut v = BTreeSet::new(); assert!(v.is_empty()); v.insert(1); assert!(!v.is_empty()); }

use std::collections::BTreeSet;

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

fn clear(&mut self)

Clears the set, removing all values.

Examples

fn main() { use std::collections::BTreeSet; let mut v = BTreeSet::new(); v.insert(1); v.clear(); assert!(v.is_empty()); }

use std::collections::BTreeSet;

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

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.

Examples

fn main() { 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); }

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);

fn get<Q>(&self, value: &Q) -> Option<&T> where T: Borrow<Q>, Q: Ord + ?Sized

Unstable (set_recovery #28050)

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.

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

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

Examples

fn main() { 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); }

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);

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

Returns true if the set is a subset of another.

Examples

fn main() { 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); }

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);

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

Returns true if the set is a superset of another.

Examples

fn main() { 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); }

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);

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

Adds a value to the set.

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

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

Examples

fn main() { 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); }

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);

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

Unstable (set_recovery #28050)

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

fn remove<Q>(&mut self, value: &Q) -> bool where Q: Ord + ?Sized, T: Borrow<Q>

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

fn main() { use std::collections::BTreeSet; let mut set = BTreeSet::new(); set.insert(2); assert_eq!(set.remove(&2), true); assert_eq!(set.remove(&2), false); }

use std::collections::BTreeSet;

let mut set = BTreeSet::new();

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

fn take<Q>(&mut self, value: &Q) -> Option<T> where T: Borrow<Q>, Q: Ord + ?Sized

Unstable (set_recovery #28050)

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.

Trait Implementations

impl<T> FromIterator<T> for BTreeSet<T> where T: Ord

fn from_iter<I>(iter: I) -> BTreeSet<T> where I: IntoIterator<Item=T>

impl<T> IntoIterator for BTreeSet<T>

type Item = T

type IntoIter = IntoIter<T>

fn into_iter(self) -> IntoIter<T>

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

type Item = &'a T

type IntoIter = Iter<'a, T>

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

impl<T> Extend<T> for BTreeSet<T> where T: Ord

fn extend<Iter>(&mut self, iter: Iter) where Iter: IntoIterator<Item=T>

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

fn extend<I>(&mut self, iter: I) where I: IntoIterator<Item=&'a T>

impl<T> Default for BTreeSet<T> where T: Ord

fn default() -> BTreeSet<T>

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

type Output = BTreeSet<T>

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

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

type Output = BTreeSet<T>

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

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

type Output = BTreeSet<T>

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

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

type Output = BTreeSet<T>

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

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

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Derived Implementations

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

fn partial_cmp(&self, __arg_0: &BTreeSet<T>) -> Option<Ordering>

fn lt(&self, __arg_0: &BTreeSet<T>) -> bool

fn le(&self, __arg_0: &BTreeSet<T>) -> bool

fn gt(&self, __arg_0: &BTreeSet<T>) -> bool

fn ge(&self, __arg_0: &BTreeSet<T>) -> bool

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

fn cmp(&self, __arg_0: &BTreeSet<T>) -> Ordering

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

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

fn eq(&self, __arg_0: &BTreeSet<T>) -> bool

fn ne(&self, __arg_0: &BTreeSet<T>) -> bool

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

fn hash<__H>(&self, __arg_0: &mut __H) where __H: Hasher

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

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

fn clone(&self) -> BTreeSet<T>

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