Struct TrackedSet

Source

pub struct TrackedSet { /* private fields */ }

Expand description

A BTreeSet<String> that records the members it gained or lost.

Implementations§

Source §

impl TrackedSet

Source

pub fn insert(&mut self, k: String) -> bool

Source

pub fn remove<Q>(&mut self, k: &Q) -> bool
where String: Borrow<Q>, Q: Ord + ?Sized + ToOwned<Owned = String>,

Source

pub fn clear(&mut self)

Source

pub fn sync_to<'a>(&mut self, members: impl IntoIterator<Item = &'a String>)

Become exactly members, which must be sorted and free of duplicates (a BTreeMap’s or BTreeSet’s keys). One merge walk: only the members gained or lost are copied, so a set of a million that did not change costs comparisons, not a million allocations.

Methods from Deref<Target = BTreeSet<String>>§

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 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));

1.0.0 · 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 · 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 · 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)

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 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)

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);