Struct std::collections::BTreeSet

1.0.0 · source ·
pub struct BTreeSet<T, A = Global>
where A: Allocator + Clone,
{ /* private fields */ }
Expand description

An ordered 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. The behavior resulting from such a logic error is not specified, but will be encapsulated to the BTreeSet that observed the logic error and not result in undefined behavior. This could include panics, incorrect results, aborts, memory leaks, and non-termination.

Iterators returned by BTreeSet::iter and BTreeSet::into_iter produce their items in order, and take worst-case logarithmic and amortized constant time per item returned.

§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}");
}

A BTreeSet with a known list of items can be initialized from an array:

use std::collections::BTreeSet;

let set = BTreeSet::from([1, 2, 3]);

Implementations§

source§

impl<T> BTreeSet<T>

1.0.0 (const: 1.66.0) · source

pub const fn new() -> BTreeSet<T>

Makes a new, empty BTreeSet.

Does not allocate anything on its own.

§Examples
use std::collections::BTreeSet;

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

impl<T, A> BTreeSet<T, A>
where A: Allocator + Clone,

source

pub const fn new_in(alloc: A) -> BTreeSet<T, A>

🔬This is a nightly-only experimental API. (btreemap_alloc #32838)

Makes a new BTreeSet with a reasonable choice of B.

§Examples
use std::collections::BTreeSet;
use std::alloc::Global;

let mut set: BTreeSet<i32> = BTreeSet::new_in(Global);
1.17.0 · source

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

§Panics

Panics if range start > end. Panics if range start == end and both bounds are Excluded.

§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());
1.0.0 · source

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

Visits the elements representing the difference, i.e., the elements 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]);
1.0.0 · source

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

Visits the elements representing the symmetric difference, i.e., the elements 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]);
1.0.0 · source

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

Visits the elements representing the intersection, i.e., the elements 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]);
1.0.0 · source

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

Visits the elements representing the union, i.e., all the elements 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]);
1.0.0 · source

pub fn clear(&mut self)
where A: Clone,

Clears the set, removing all elements.

§Examples
use std::collections::BTreeSet;

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

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

Returns true if the set contains an element equal to the value.

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

§Examples
use std::collections::BTreeSet;

let set = BTreeSet::from([1, 2, 3]);
assert_eq!(set.contains(&1), true);
assert_eq!(set.contains(&4), false);
1.9.0 · source

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

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

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

§Examples
use std::collections::BTreeSet;

let set = BTreeSet::from([1, 2, 3]);
assert_eq!(set.get(&2), Some(&2));
assert_eq!(set.get(&4), None);
1.0.0 · source

pub fn is_disjoint(&self, other: &BTreeSet<T, A>) -> 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::from([1, 2, 3]);
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);
1.0.0 · source

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

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

§Examples
use std::collections::BTreeSet;

let sup = BTreeSet::from([1, 2, 3]);
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);
1.0.0 · source

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

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

§Examples
use std::collections::BTreeSet;

let sub = BTreeSet::from([1, 2]);
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);
1.66.0 · source

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

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

§Examples

Basic usage:

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));
1.66.0 · source

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

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

§Examples

Basic usage:

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));
1.66.0 · source

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

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

§Examples
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());
1.66.0 · source

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

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

§Examples
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());
1.0.0 · source

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

Adds a value to the set.

Returns whether the value was newly inserted. That is:

  • If the set did not previously contain an equal value, true is returned.
  • If the set already contained an equal value, 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);
1.9.0 · source

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

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

§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);
1.0.0 · source

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

If the set contains an element equal to the value, removes it from the set and drops it. Returns whether such an element was present.

The value may be any borrowed form of the set’s element type, but the ordering on the borrowed form must match the ordering on the element 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);
1.9.0 · source

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

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

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

§Examples
use std::collections::BTreeSet;

let mut set = BTreeSet::from([1, 2, 3]);
assert_eq!(set.take(&2), Some(2));
assert_eq!(set.take(&2), None);
1.53.0 · source

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 for which f(&e) returns false. The elements are visited in ascending order.

§Examples
use std::collections::BTreeSet;

let mut set = BTreeSet::from([1, 2, 3, 4, 5, 6]);
// Keep only the even numbers.
set.retain(|&k| k % 2 == 0);
assert!(set.iter().eq([2, 4, 6].iter()));
1.11.0 · source

pub fn append(&mut self, other: &mut BTreeSet<T, A>)
where T: Ord, A: Clone,

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));
1.11.0 · source

pub fn split_off<Q>(&mut self, value: &Q) -> BTreeSet<T, A>
where Q: Ord + ?Sized, T: Borrow<Q> + Ord, A: Clone,

Splits the collection into two at the value. Returns a new collection with all elements greater than or equal to 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));
source

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

🔬This is a nightly-only experimental API. (btree_extract_if #70530)

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

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

If the returned ExtractIf is not exhausted, e.g. because it is dropped without iterating or the iteration short-circuits, then the remaining elements will be retained. Use retain with a negated predicate if you do not need the returned iterator.

§Examples

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

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

let mut set: BTreeSet<i32> = (0..8).collect();
let evens: BTreeSet<_> = set.extract_if(|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]);
1.0.0 · source

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

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

§Examples
use std::collections::BTreeSet;

let set = BTreeSet::from([3, 1, 2]);
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);
1.0.0 (const: unstable) · source

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);
1.0.0 (const: unstable) · source

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());
source

pub fn lower_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, T>
where T: Borrow<Q> + Ord, Q: Ord + ?Sized,

🔬This is a nightly-only experimental API. (btree_cursors #107540)

Returns a Cursor pointing at the gap before the smallest element greater than the given bound.

Passing Bound::Included(x) will return a cursor pointing to the gap before the smallest element greater than or equal to x.

Passing Bound::Excluded(x) will return a cursor pointing to the gap before the smallest element greater than x.

Passing Bound::Unbounded will return a cursor pointing to the gap before the smallest element in the set.

§Examples
#![feature(btree_cursors)]

use std::collections::BTreeSet;
use std::ops::Bound;

let set = BTreeSet::from([1, 2, 3, 4]);

let cursor = set.lower_bound(Bound::Included(&2));
assert_eq!(cursor.peek_prev(), Some(&1));
assert_eq!(cursor.peek_next(), Some(&2));

let cursor = set.lower_bound(Bound::Excluded(&2));
assert_eq!(cursor.peek_prev(), Some(&2));
assert_eq!(cursor.peek_next(), Some(&3));

let cursor = set.lower_bound(Bound::Unbounded);
assert_eq!(cursor.peek_prev(), None);
assert_eq!(cursor.peek_next(), Some(&1));
source

pub fn lower_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, T, A>
where T: Borrow<Q> + Ord, Q: Ord + ?Sized,

🔬This is a nightly-only experimental API. (btree_cursors #107540)

Returns a CursorMut pointing at the gap before the smallest element greater than the given bound.

Passing Bound::Included(x) will return a cursor pointing to the gap before the smallest element greater than or equal to x.

Passing Bound::Excluded(x) will return a cursor pointing to the gap before the smallest element greater than x.

Passing Bound::Unbounded will return a cursor pointing to the gap before the smallest element in the set.

§Examples
#![feature(btree_cursors)]

use std::collections::BTreeSet;
use std::ops::Bound;

let mut set = BTreeSet::from([1, 2, 3, 4]);

let mut cursor = set.lower_bound_mut(Bound::Included(&2));
assert_eq!(cursor.peek_prev(), Some(&1));
assert_eq!(cursor.peek_next(), Some(&2));

let mut cursor = set.lower_bound_mut(Bound::Excluded(&2));
assert_eq!(cursor.peek_prev(), Some(&2));
assert_eq!(cursor.peek_next(), Some(&3));

let mut cursor = set.lower_bound_mut(Bound::Unbounded);
assert_eq!(cursor.peek_prev(), None);
assert_eq!(cursor.peek_next(), Some(&1));
source

pub fn upper_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, T>
where T: Borrow<Q> + Ord, Q: Ord + ?Sized,

🔬This is a nightly-only experimental API. (btree_cursors #107540)

Returns a Cursor pointing at the gap after the greatest element smaller than the given bound.

Passing Bound::Included(x) will return a cursor pointing to the gap after the greatest element smaller than or equal to x.

Passing Bound::Excluded(x) will return a cursor pointing to the gap after the greatest element smaller than x.

Passing Bound::Unbounded will return a cursor pointing to the gap after the greatest element in the set.

§Examples
#![feature(btree_cursors)]

use std::collections::BTreeSet;
use std::ops::Bound;

let set = BTreeSet::from([1, 2, 3, 4]);

let cursor = set.upper_bound(Bound::Included(&3));
assert_eq!(cursor.peek_prev(), Some(&3));
assert_eq!(cursor.peek_next(), Some(&4));

let cursor = set.upper_bound(Bound::Excluded(&3));
assert_eq!(cursor.peek_prev(), Some(&2));
assert_eq!(cursor.peek_next(), Some(&3));

let cursor = set.upper_bound(Bound::Unbounded);
assert_eq!(cursor.peek_prev(), Some(&4));
assert_eq!(cursor.peek_next(), None);
source

pub unsafe fn upper_bound_mut<Q>( &mut self, bound: Bound<&Q>, ) -> CursorMut<'_, T, A>
where T: Borrow<Q> + Ord, Q: Ord + ?Sized,

🔬This is a nightly-only experimental API. (btree_cursors #107540)

Returns a CursorMut pointing at the gap after the greatest element smaller than the given bound.

Passing Bound::Included(x) will return a cursor pointing to the gap after the greatest element smaller than or equal to x.

Passing Bound::Excluded(x) will return a cursor pointing to the gap after the greatest element smaller than x.

Passing Bound::Unbounded will return a cursor pointing to the gap after the greatest element in the set.

§Examples
#![feature(btree_cursors)]

use std::collections::BTreeSet;
use std::ops::Bound;

let mut set = BTreeSet::from([1, 2, 3, 4]);

let mut cursor = unsafe { set.upper_bound_mut(Bound::Included(&3)) };
assert_eq!(cursor.peek_prev(), Some(&3));
assert_eq!(cursor.peek_next(), Some(&4));

let mut cursor = unsafe { set.upper_bound_mut(Bound::Excluded(&3)) };
assert_eq!(cursor.peek_prev(), Some(&2));
assert_eq!(cursor.peek_next(), Some(&3));

let mut cursor = unsafe { set.upper_bound_mut(Bound::Unbounded) };
assert_eq!(cursor.peek_prev(), Some(&4));
assert_eq!(cursor.peek_next(), None);

Trait Implementations§

1.0.0 · source§

impl<T, A> BitAnd<&BTreeSet<T, A>> for &BTreeSet<T, A>
where T: Ord + Clone, A: Allocator + Clone,

source§

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

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

§Examples
use std::collections::BTreeSet;

let a = BTreeSet::from([1, 2, 3]);
let b = BTreeSet::from([2, 3, 4]);

let result = &a & &b;
assert_eq!(result, BTreeSet::from([2, 3]));
source§

type Output = BTreeSet<T, A>

The resulting type after applying the & operator.
1.0.0 · source§

impl<T, A> BitOr<&BTreeSet<T, A>> for &BTreeSet<T, A>
where T: Ord + Clone, A: Allocator + Clone,

source§

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

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

§Examples
use std::collections::BTreeSet;

let a = BTreeSet::from([1, 2, 3]);
let b = BTreeSet::from([3, 4, 5]);

let result = &a | &b;
assert_eq!(result, BTreeSet::from([1, 2, 3, 4, 5]));
source§

type Output = BTreeSet<T, A>

The resulting type after applying the | operator.
1.0.0 · source§

impl<T, A> BitXor<&BTreeSet<T, A>> for &BTreeSet<T, A>
where T: Ord + Clone, A: Allocator + Clone,

source§

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

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

§Examples
use std::collections::BTreeSet;

let a = BTreeSet::from([1, 2, 3]);
let b = BTreeSet::from([2, 3, 4]);

let result = &a ^ &b;
assert_eq!(result, BTreeSet::from([1, 4]));
source§

type Output = BTreeSet<T, A>

The resulting type after applying the ^ operator.
1.0.0 · source§

impl<T, A> Clone for BTreeSet<T, A>
where T: Clone, A: Allocator + Clone,

source§

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

Returns a copy of the value. Read more
source§

fn clone_from(&mut self, source: &BTreeSet<T, A>)

Performs copy-assignment from source. Read more
1.0.0 · source§

impl<T, A> Debug for BTreeSet<T, A>
where T: Debug, A: Allocator + Clone,

source§

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

Formats the value using the given formatter. Read more
1.0.0 · source§

impl<T> Default for BTreeSet<T>

source§

fn default() -> BTreeSet<T>

Creates an empty BTreeSet.

1.2.0 · source§

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

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

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

fn extend_one(&mut self, _: &'a T)

🔬This is a nightly-only experimental API. (extend_one #72631)
Extends a collection with exactly one element.
source§

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one #72631)
Reserves capacity in a collection for the given number of additional elements. Read more
1.0.0 · source§

impl<T, A> Extend<T> for BTreeSet<T, A>
where T: Ord, A: Allocator + Clone,

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

Extends a collection with the contents of an iterator. Read more
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fn extend_one(&mut self, elem: T)

🔬This is a nightly-only experimental API. (extend_one #72631)
Extends a collection with exactly one element.
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fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one #72631)
Reserves capacity in a collection for the given number of additional elements. Read more
1.56.0 · source§

impl<T, const N: usize> From<[T; N]> for BTreeSet<T>
where T: Ord,

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fn from(arr: [T; N]) -> BTreeSet<T>

Converts a [T; N] into a BTreeSet<T>.

use std::collections::BTreeSet;

let set1 = BTreeSet::from([1, 2, 3, 4]);
let set2: BTreeSet<_> = [1, 2, 3, 4].into();
assert_eq!(set1, set2);
1.0.0 · source§

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

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

Creates a value from an iterator. Read more
1.0.0 · source§

impl<T, A> Hash for BTreeSet<T, A>
where T: Hash, A: Allocator + Clone,

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

Feeds this value into the given Hasher. Read more
1.3.0 · source§

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

Feeds a slice of this type into the given Hasher. Read more
1.0.0 · source§

impl<'a, T, A> IntoIterator for &'a BTreeSet<T, A>
where A: Allocator + Clone,

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type Item = &'a T

The type of the elements being iterated over.
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type IntoIter = Iter<'a, T>

Which kind of iterator are we turning this into?
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fn into_iter(self) -> Iter<'a, T>

Creates an iterator from a value. Read more
1.0.0 · source§

impl<T, A> IntoIterator for BTreeSet<T, A>
where A: Allocator + Clone,

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

Gets an iterator for moving out the BTreeSet’s contents in ascending order.

§Examples
use std::collections::BTreeSet;

let set = BTreeSet::from([1, 2, 3, 4]);

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

The type of the elements being iterated over.
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type IntoIter = IntoIter<T, A>

Which kind of iterator are we turning this into?
1.0.0 · source§

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

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

This method returns an Ordering between self and other. Read more
1.21.0 · source§

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

Compares and returns the maximum of two values. Read more
1.21.0 · source§

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

Compares and returns the minimum of two values. Read more
1.50.0 · source§

fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
1.0.0 · source§

impl<T, A> PartialEq for BTreeSet<T, A>
where T: PartialEq, A: Allocator + Clone,

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

Tests for self and other values to be equal, and is used by ==.
1.0.0 · source§

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

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

impl<T, A> PartialOrd for BTreeSet<T, A>
where T: PartialOrd, A: Allocator + Clone,

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

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

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

Tests less than (for self and other) and is used by the < operator. Read more
1.0.0 · source§

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

Tests less than or equal to (for self and other) and is used by the <= operator. Read more
1.0.0 · source§

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

Tests greater than (for self and other) and is used by the > operator. Read more
1.0.0 · source§

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

Tests greater than or equal to (for self and other) and is used by the >= operator. Read more
1.0.0 · source§

impl<T, A> Sub<&BTreeSet<T, A>> for &BTreeSet<T, A>
where T: Ord + Clone, A: Allocator + Clone,

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

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

§Examples
use std::collections::BTreeSet;

let a = BTreeSet::from([1, 2, 3]);
let b = BTreeSet::from([3, 4, 5]);

let result = &a - &b;
assert_eq!(result, BTreeSet::from([1, 2]));
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type Output = BTreeSet<T, A>

The resulting type after applying the - operator.
1.0.0 · source§

impl<T, A> Eq for BTreeSet<T, A>
where T: Eq, A: Allocator + Clone,

Auto Trait Implementations§

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impl<T, A> Freeze for BTreeSet<T, A>
where A: Freeze,

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impl<T, A> RefUnwindSafe for BTreeSet<T, A>

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

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

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

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impl<T, A> UnwindSafe for BTreeSet<T, A>

Blanket Implementations§

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

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit #126799)
Performs copy-assignment from self to dst. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.