pub struct BTreeSet<T, A = Global>{ /* 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, A> BTreeSet<T, A>
impl<T, A> BTreeSet<T, A>
Sourcepub const fn new_in(alloc: A) -> BTreeSet<T, A>
🔬This is a nightly-only experimental API. (btreemap_alloc
)Available on non-no_global_oom_handling
only.
pub const fn new_in(alloc: A) -> BTreeSet<T, A>
btreemap_alloc
)no_global_oom_handling
only.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 · Sourcepub fn range<K, R>(&self, range: R) -> Range<'_, T> ⓘ
Available on non-no_global_oom_handling
only.
pub fn range<K, R>(&self, range: R) -> Range<'_, T> ⓘ
no_global_oom_handling
only.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 · Sourcepub fn difference<'a>(
&'a self,
other: &'a BTreeSet<T, A>,
) -> Difference<'a, T, A> ⓘwhere
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn difference<'a>(
&'a self,
other: &'a BTreeSet<T, A>,
) -> Difference<'a, T, A> ⓘwhere
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn symmetric_difference<'a>(
&'a self,
other: &'a BTreeSet<T, A>,
) -> SymmetricDifference<'a, T> ⓘwhere
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn symmetric_difference<'a>(
&'a self,
other: &'a BTreeSet<T, A>,
) -> SymmetricDifference<'a, T> ⓘwhere
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn intersection<'a>(
&'a self,
other: &'a BTreeSet<T, A>,
) -> Intersection<'a, T, A> ⓘwhere
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn intersection<'a>(
&'a self,
other: &'a BTreeSet<T, A>,
) -> Intersection<'a, T, A> ⓘwhere
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn union<'a>(&'a self, other: &'a BTreeSet<T, A>) -> Union<'a, T> ⓘwhere
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn union<'a>(&'a self, other: &'a BTreeSet<T, A>) -> Union<'a, T> ⓘwhere
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn clear(&mut self)where
A: Clone,
Available on non-no_global_oom_handling
only.
pub fn clear(&mut self)where
A: Clone,
no_global_oom_handling
only.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 · Sourcepub fn contains<Q>(&self, value: &Q) -> bool
Available on non-no_global_oom_handling
only.
pub fn contains<Q>(&self, value: &Q) -> bool
no_global_oom_handling
only.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 · Sourcepub fn get<Q>(&self, value: &Q) -> Option<&T>
Available on non-no_global_oom_handling
only.
pub fn get<Q>(&self, value: &Q) -> Option<&T>
no_global_oom_handling
only.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 · Sourcepub fn is_disjoint(&self, other: &BTreeSet<T, A>) -> boolwhere
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn is_disjoint(&self, other: &BTreeSet<T, A>) -> boolwhere
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn is_subset(&self, other: &BTreeSet<T, A>) -> boolwhere
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn is_subset(&self, other: &BTreeSet<T, A>) -> boolwhere
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn is_superset(&self, other: &BTreeSet<T, A>) -> boolwhere
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn is_superset(&self, other: &BTreeSet<T, A>) -> boolwhere
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn first(&self) -> Option<&T>where
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn first(&self) -> Option<&T>where
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn last(&self) -> Option<&T>where
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn last(&self) -> Option<&T>where
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn pop_first(&mut self) -> Option<T>where
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn pop_first(&mut self) -> Option<T>where
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn pop_last(&mut self) -> Option<T>where
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn pop_last(&mut self) -> Option<T>where
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn insert(&mut self, value: T) -> boolwhere
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn insert(&mut self, value: T) -> boolwhere
T: Ord,
no_global_oom_handling
only.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 · Sourcepub fn replace(&mut self, value: T) -> Option<T>where
T: Ord,
Available on non-no_global_oom_handling
only.
pub fn replace(&mut self, value: T) -> Option<T>where
T: Ord,
no_global_oom_handling
only.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);
Sourcepub fn get_or_insert(&mut self, value: T) -> &Twhere
T: Ord,
🔬This is a nightly-only experimental API. (btree_set_entry
)Available on non-no_global_oom_handling
only.
pub fn get_or_insert(&mut self, value: T) -> &Twhere
T: Ord,
btree_set_entry
)no_global_oom_handling
only.Inserts the given value
into the set if it is not present, then
returns a reference to the value in the set.
§Examples
#![feature(btree_set_entry)]
use std::collections::BTreeSet;
let mut set = BTreeSet::from([1, 2, 3]);
assert_eq!(set.len(), 3);
assert_eq!(set.get_or_insert(2), &2);
assert_eq!(set.get_or_insert(100), &100);
assert_eq!(set.len(), 4); // 100 was inserted
Sourcepub fn get_or_insert_with<Q, F>(&mut self, value: &Q, f: F) -> &T
🔬This is a nightly-only experimental API. (btree_set_entry
)Available on non-no_global_oom_handling
only.
pub fn get_or_insert_with<Q, F>(&mut self, value: &Q, f: F) -> &T
btree_set_entry
)no_global_oom_handling
only.Inserts a value computed from f
into the set if the given value
is
not present, then returns a reference to the value in the set.
§Examples
#![feature(btree_set_entry)]
use std::collections::BTreeSet;
let mut set: BTreeSet<String> = ["cat", "dog", "horse"]
.iter().map(|&pet| pet.to_owned()).collect();
assert_eq!(set.len(), 3);
for &pet in &["cat", "dog", "fish"] {
let value = set.get_or_insert_with(pet, str::to_owned);
assert_eq!(value, pet);
}
assert_eq!(set.len(), 4); // a new "fish" was inserted
Sourcepub fn entry(&mut self, value: T) -> Entry<'_, T, A>where
T: Ord,
🔬This is a nightly-only experimental API. (btree_set_entry
)Available on non-no_global_oom_handling
only.
pub fn entry(&mut self, value: T) -> Entry<'_, T, A>where
T: Ord,
btree_set_entry
)no_global_oom_handling
only.Gets the given value’s corresponding entry in the set for in-place manipulation.
§Examples
#![feature(btree_set_entry)]
use std::collections::BTreeSet;
use std::collections::btree_set::Entry::*;
let mut singles = BTreeSet::new();
let mut dupes = BTreeSet::new();
for ch in "a short treatise on fungi".chars() {
if let Vacant(dupe_entry) = dupes.entry(ch) {
// We haven't already seen a duplicate, so
// check if we've at least seen it once.
match singles.entry(ch) {
Vacant(single_entry) => {
// We found a new character for the first time.
single_entry.insert()
}
Occupied(single_entry) => {
// We've already seen this once, "move" it to dupes.
single_entry.remove();
dupe_entry.insert();
}
}
}
}
assert!(!singles.contains(&'t') && dupes.contains(&'t'));
assert!(singles.contains(&'u') && !dupes.contains(&'u'));
assert!(!singles.contains(&'v') && !dupes.contains(&'v'));
1.0.0 · Sourcepub fn remove<Q>(&mut self, value: &Q) -> bool
Available on non-no_global_oom_handling
only.
pub fn remove<Q>(&mut self, value: &Q) -> bool
no_global_oom_handling
only.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 · Sourcepub fn take<Q>(&mut self, value: &Q) -> Option<T>
Available on non-no_global_oom_handling
only.
pub fn take<Q>(&mut self, value: &Q) -> Option<T>
no_global_oom_handling
only.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 · Sourcepub fn retain<F>(&mut self, f: F)
Available on non-no_global_oom_handling
only.
pub fn retain<F>(&mut self, f: F)
no_global_oom_handling
only.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 · Sourcepub fn append(&mut self, other: &mut BTreeSet<T, A>)
Available on non-no_global_oom_handling
only.
pub fn append(&mut self, other: &mut BTreeSet<T, A>)
no_global_oom_handling
only.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 · Sourcepub fn split_off<Q>(&mut self, value: &Q) -> BTreeSet<T, A>
Available on non-no_global_oom_handling
only.
pub fn split_off<Q>(&mut self, value: &Q) -> BTreeSet<T, A>
no_global_oom_handling
only.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));
Sourcepub fn extract_if<'a, F>(&'a mut self, pred: F) -> ExtractIf<'a, T, F, A> ⓘ
🔬This is a nightly-only experimental API. (btree_extract_if
)Available on non-no_global_oom_handling
only.
pub fn extract_if<'a, F>(&'a mut self, pred: F) -> ExtractIf<'a, T, F, A> ⓘ
btree_extract_if
)no_global_oom_handling
only.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 · Sourcepub fn iter(&self) -> Iter<'_, T> ⓘ
Available on non-no_global_oom_handling
only.
pub fn iter(&self) -> Iter<'_, T> ⓘ
no_global_oom_handling
only.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) · Sourcepub fn len(&self) -> usize
Available on non-no_global_oom_handling
only.
pub fn len(&self) -> usize
no_global_oom_handling
only.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) · Sourcepub fn is_empty(&self) -> bool
Available on non-no_global_oom_handling
only.
pub fn is_empty(&self) -> bool
no_global_oom_handling
only.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());
Sourcepub fn lower_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, T>
🔬This is a nightly-only experimental API. (btree_cursors
)Available on non-no_global_oom_handling
only.
pub fn lower_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, T>
btree_cursors
)no_global_oom_handling
only.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));
Sourcepub fn lower_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, T, A>
🔬This is a nightly-only experimental API. (btree_cursors
)Available on non-no_global_oom_handling
only.
pub fn lower_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, T, A>
btree_cursors
)no_global_oom_handling
only.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));
Sourcepub fn upper_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, T>
🔬This is a nightly-only experimental API. (btree_cursors
)Available on non-no_global_oom_handling
only.
pub fn upper_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, T>
btree_cursors
)no_global_oom_handling
only.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);
Sourcepub fn upper_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, T, A>
🔬This is a nightly-only experimental API. (btree_cursors
)Available on non-no_global_oom_handling
only.
pub fn upper_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, T, A>
btree_cursors
)no_global_oom_handling
only.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 = set.upper_bound_mut(Bound::Included(&3));
assert_eq!(cursor.peek_prev(), Some(&3));
assert_eq!(cursor.peek_next(), Some(&4));
let mut cursor = set.upper_bound_mut(Bound::Excluded(&3));
assert_eq!(cursor.peek_prev(), Some(&2));
assert_eq!(cursor.peek_next(), Some(&3));
let mut cursor = 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>
impl<T, A> BitAnd<&BTreeSet<T, A>> for &BTreeSet<T, A>
Source§fn bitand(self, rhs: &BTreeSet<T, A>) -> BTreeSet<T, A>
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]));
1.0.0 · Source§impl<T, A> BitOr<&BTreeSet<T, A>> for &BTreeSet<T, A>
impl<T, A> BitOr<&BTreeSet<T, A>> for &BTreeSet<T, A>
Source§fn bitor(self, rhs: &BTreeSet<T, A>) -> BTreeSet<T, A>
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]));
1.0.0 · Source§impl<T, A> BitXor<&BTreeSet<T, A>> for &BTreeSet<T, A>
impl<T, A> BitXor<&BTreeSet<T, A>> for &BTreeSet<T, A>
Source§fn bitxor(self, rhs: &BTreeSet<T, A>) -> BTreeSet<T, A>
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]));
1.2.0 · Source§impl<'a, T, A> Extend<&'a T> for BTreeSet<T, A>
impl<'a, T, A> Extend<&'a T> for BTreeSet<T, A>
Source§fn extend<I>(&mut self, iter: I)where
I: IntoIterator<Item = &'a T>,
fn extend<I>(&mut self, iter: I)where
I: IntoIterator<Item = &'a T>,
Source§fn extend_one(&mut self, _: &'a T)
fn extend_one(&mut self, _: &'a T)
extend_one
)Source§fn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)1.0.0 · Source§impl<T, A> Extend<T> for BTreeSet<T, A>
impl<T, A> Extend<T> for BTreeSet<T, A>
Source§fn extend<Iter>(&mut self, iter: Iter)where
Iter: IntoIterator<Item = T>,
fn extend<Iter>(&mut self, iter: Iter)where
Iter: IntoIterator<Item = T>,
Source§fn extend_one(&mut self, elem: T)
fn extend_one(&mut self, elem: T)
extend_one
)Source§fn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)1.56.0 · Source§impl<T, const N: usize> From<[T; N]> for BTreeSet<T>where
T: Ord,
impl<T, const N: usize> From<[T; N]> for BTreeSet<T>where
T: Ord,
Source§fn from(arr: [T; N]) -> BTreeSet<T>
fn from(arr: [T; N]) -> BTreeSet<T>
Converts a [T; N]
into a BTreeSet<T>
.
If the array contains any equal values, all but one will be dropped.
§Examples
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,
impl<T> FromIterator<T> for BTreeSet<T>where
T: Ord,
1.0.0 · Source§impl<'a, T, A> IntoIterator for &'a BTreeSet<T, A>
impl<'a, T, A> IntoIterator for &'a BTreeSet<T, A>
1.0.0 · Source§impl<T, A> IntoIterator for BTreeSet<T, A>
impl<T, A> IntoIterator for BTreeSet<T, A>
1.0.0 · Source§impl<T, A> Ord for BTreeSet<T, A>
impl<T, A> Ord for BTreeSet<T, A>
1.21.0 · Source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
1.0.0 · Source§impl<T, A> PartialOrd for BTreeSet<T, A>
impl<T, A> PartialOrd for BTreeSet<T, A>
1.0.0 · Source§impl<T, A> Sub<&BTreeSet<T, A>> for &BTreeSet<T, A>
impl<T, A> Sub<&BTreeSet<T, A>> for &BTreeSet<T, A>
impl<T, A> Eq for BTreeSet<T, A>
Auto Trait Implementations§
impl<T, A> Freeze for BTreeSet<T, A>where
A: Freeze,
impl<T, A> RefUnwindSafe for BTreeSet<T, A>where
A: RefUnwindSafe,
T: RefUnwindSafe,
impl<T, A> Send for BTreeSet<T, A>
impl<T, A> Sync for BTreeSet<T, A>
impl<T, A> Unpin for BTreeSet<T, A>where
A: Unpin,
impl<T, A> UnwindSafe for BTreeSet<T, A>where
A: UnwindSafe,
T: RefUnwindSafe,
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Source§impl<T> ChainInner for T
impl<T> ChainInner for T
Source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
§impl<Q, K> Comparable<K> for Q
impl<Q, K> Comparable<K> for Q
§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key
and return true
if they are equal.