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.
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());
Visits the values representing the difference,
i.e. the values that are in self but not in other,
in ascending order.
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]);
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.
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]);
Visits the values representing the intersection,
i.e. the values that are both in self and other,
in ascending order.
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]);
Visits the values representing the union,
i.e. all the values in self or other, without duplicates,
in ascending order.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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));
Gets an iterator that visits the values in the BTreeSet in ascending order.
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.
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.
use std::collections::BTreeSet;
let mut v = BTreeSet::new();
assert!(v.is_empty());
v.insert(1);
assert!(!v.is_empty());