| // This is pretty much entirely stolen from TreeSet, since BTreeMap has an identical interface |
| // to TreeMap |
| |
| use core::borrow::Borrow; |
| use core::cmp::Ordering::{self, Less, Greater, Equal}; |
| use core::cmp::{max, min}; |
| use core::fmt::{self, Debug}; |
| use core::iter::{Peekable, FromIterator, FusedIterator}; |
| use core::ops::{BitOr, BitAnd, BitXor, Sub, RangeBounds}; |
| |
| use crate::collections::btree_map::{self, BTreeMap, Keys}; |
| use super::Recover; |
| |
| // FIXME(conventions): implement bounded iterators |
| |
| /// 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. |
| /// |
| /// [`BTreeMap`]: struct.BTreeMap.html |
| /// [`Ord`]: ../../std/cmp/trait.Ord.html |
| /// [`Cell`]: ../../std/cell/struct.Cell.html |
| /// [`RefCell`]: ../../std/cell/struct.RefCell.html |
| /// |
| /// # 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); |
| /// } |
| /// ``` |
| #[derive(Clone, Hash, PartialEq, Eq, Ord, PartialOrd)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct BTreeSet<T> { |
| map: BTreeMap<T, ()>, |
| } |
| |
| /// An iterator over the items of a `BTreeSet`. |
| /// |
| /// This `struct` is created by the [`iter`] method on [`BTreeSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`BTreeSet`]: struct.BTreeSet.html |
| /// [`iter`]: struct.BTreeSet.html#method.iter |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct Iter<'a, T: 'a> { |
| iter: Keys<'a, T, ()>, |
| } |
| |
| #[stable(feature = "collection_debug", since = "1.17.0")] |
| impl<T: fmt::Debug> fmt::Debug for Iter<'_, T> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.debug_tuple("Iter") |
| .field(&self.iter.clone()) |
| .finish() |
| } |
| } |
| |
| /// An owning iterator over the items of a `BTreeSet`. |
| /// |
| /// This `struct` is created by the [`into_iter`] method on [`BTreeSet`][`BTreeSet`] |
| /// (provided by the `IntoIterator` trait). See its documentation for more. |
| /// |
| /// [`BTreeSet`]: struct.BTreeSet.html |
| /// [`into_iter`]: struct.BTreeSet.html#method.into_iter |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[derive(Debug)] |
| pub struct IntoIter<T> { |
| iter: btree_map::IntoIter<T, ()>, |
| } |
| |
| /// An iterator over a sub-range of items in a `BTreeSet`. |
| /// |
| /// This `struct` is created by the [`range`] method on [`BTreeSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`BTreeSet`]: struct.BTreeSet.html |
| /// [`range`]: struct.BTreeSet.html#method.range |
| #[derive(Debug)] |
| #[stable(feature = "btree_range", since = "1.17.0")] |
| pub struct Range<'a, T: 'a> { |
| iter: btree_map::Range<'a, T, ()>, |
| } |
| |
| /// A lazy iterator producing elements in the difference of `BTreeSet`s. |
| /// |
| /// This `struct` is created by the [`difference`] method on [`BTreeSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`BTreeSet`]: struct.BTreeSet.html |
| /// [`difference`]: struct.BTreeSet.html#method.difference |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct Difference<'a, T: 'a> { |
| inner: DifferenceInner<'a, T>, |
| } |
| enum DifferenceInner<'a, T: 'a> { |
| Stitch { |
| self_iter: Iter<'a, T>, |
| other_iter: Peekable<Iter<'a, T>>, |
| }, |
| Search { |
| self_iter: Iter<'a, T>, |
| other_set: &'a BTreeSet<T>, |
| }, |
| } |
| |
| #[stable(feature = "collection_debug", since = "1.17.0")] |
| impl<T: fmt::Debug> fmt::Debug for Difference<'_, T> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match &self.inner { |
| DifferenceInner::Stitch { |
| self_iter, |
| other_iter, |
| } => f |
| .debug_tuple("Difference") |
| .field(&self_iter) |
| .field(&other_iter) |
| .finish(), |
| DifferenceInner::Search { |
| self_iter, |
| other_set: _, |
| } => f.debug_tuple("Difference").field(&self_iter).finish(), |
| } |
| } |
| } |
| |
| /// A lazy iterator producing elements in the symmetric difference of `BTreeSet`s. |
| /// |
| /// This `struct` is created by the [`symmetric_difference`] method on |
| /// [`BTreeSet`]. See its documentation for more. |
| /// |
| /// [`BTreeSet`]: struct.BTreeSet.html |
| /// [`symmetric_difference`]: struct.BTreeSet.html#method.symmetric_difference |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct SymmetricDifference<'a, T: 'a> { |
| a: Peekable<Iter<'a, T>>, |
| b: Peekable<Iter<'a, T>>, |
| } |
| |
| #[stable(feature = "collection_debug", since = "1.17.0")] |
| impl<T: fmt::Debug> fmt::Debug for SymmetricDifference<'_, T> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.debug_tuple("SymmetricDifference") |
| .field(&self.a) |
| .field(&self.b) |
| .finish() |
| } |
| } |
| |
| /// A lazy iterator producing elements in the intersection of `BTreeSet`s. |
| /// |
| /// This `struct` is created by the [`intersection`] method on [`BTreeSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`BTreeSet`]: struct.BTreeSet.html |
| /// [`intersection`]: struct.BTreeSet.html#method.intersection |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct Intersection<'a, T: 'a> { |
| inner: IntersectionInner<'a, T>, |
| } |
| enum IntersectionInner<'a, T: 'a> { |
| Stitch { |
| a: Iter<'a, T>, |
| b: Iter<'a, T>, |
| }, |
| Search { |
| small_iter: Iter<'a, T>, |
| large_set: &'a BTreeSet<T>, |
| }, |
| } |
| |
| #[stable(feature = "collection_debug", since = "1.17.0")] |
| impl<T: fmt::Debug> fmt::Debug for Intersection<'_, T> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match &self.inner { |
| IntersectionInner::Stitch { |
| a, |
| b, |
| } => f |
| .debug_tuple("Intersection") |
| .field(&a) |
| .field(&b) |
| .finish(), |
| IntersectionInner::Search { |
| small_iter, |
| large_set: _, |
| } => f.debug_tuple("Intersection").field(&small_iter).finish(), |
| } |
| } |
| } |
| |
| /// A lazy iterator producing elements in the union of `BTreeSet`s. |
| /// |
| /// This `struct` is created by the [`union`] method on [`BTreeSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`BTreeSet`]: struct.BTreeSet.html |
| /// [`union`]: struct.BTreeSet.html#method.union |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct Union<'a, T: 'a> { |
| a: Peekable<Iter<'a, T>>, |
| b: Peekable<Iter<'a, T>>, |
| } |
| |
| #[stable(feature = "collection_debug", since = "1.17.0")] |
| impl<T: fmt::Debug> fmt::Debug for Union<'_, T> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.debug_tuple("Union") |
| .field(&self.a) |
| .field(&self.b) |
| .finish() |
| } |
| } |
| |
| // This constant is used by functions that compare two sets. |
| // It estimates the relative size at which searching performs better |
| // than iterating, based on the benchmarks in |
| // https://github.com/ssomers/rust_bench_btreeset_intersection; |
| // It's used to divide rather than multiply sizes, to rule out overflow, |
| // and it's a power of two to make that division cheap. |
| const ITER_PERFORMANCE_TIPPING_SIZE_DIFF: usize = 16; |
| |
| impl<T: Ord> BTreeSet<T> { |
| /// Makes a new `BTreeSet` with a reasonable choice of B. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// # #![allow(unused_mut)] |
| /// use std::collections::BTreeSet; |
| /// |
| /// let mut set: BTreeSet<i32> = BTreeSet::new(); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn new() -> BTreeSet<T> { |
| BTreeSet { map: BTreeMap::new() } |
| } |
| |
| /// 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. |
| /// |
| /// # 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()); |
| /// ``` |
| #[stable(feature = "btree_range", since = "1.17.0")] |
| pub fn range<K: ?Sized, R>(&self, range: R) -> Range<'_, T> |
| where K: Ord, T: Borrow<K>, R: RangeBounds<K> |
| { |
| Range { iter: self.map.range(range) } |
| } |
| |
| /// Visits the values representing the difference, |
| /// i.e., the values 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]); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn difference<'a>(&'a self, other: &'a BTreeSet<T>) -> Difference<'a, T> { |
| if self.len() > other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF { |
| // Self is bigger than or not much smaller than other set. |
| // Iterate both sets jointly, spotting matches along the way. |
| Difference { |
| inner: DifferenceInner::Stitch { |
| self_iter: self.iter(), |
| other_iter: other.iter().peekable(), |
| }, |
| } |
| } else { |
| // Self is much smaller than other set, or both sets are empty. |
| // Iterate the small set, searching for matches in the large set. |
| Difference { |
| inner: DifferenceInner::Search { |
| self_iter: self.iter(), |
| other_set: other, |
| }, |
| } |
| } |
| } |
| |
| /// 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. |
| /// |
| /// # 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]); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn symmetric_difference<'a>(&'a self, |
| other: &'a BTreeSet<T>) |
| -> SymmetricDifference<'a, T> { |
| SymmetricDifference { |
| a: self.iter().peekable(), |
| b: other.iter().peekable(), |
| } |
| } |
| |
| /// Visits the values representing the intersection, |
| /// i.e., the values 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]); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn intersection<'a>(&'a self, other: &'a BTreeSet<T>) -> Intersection<'a, T> { |
| let (small, other) = if self.len() <= other.len() { |
| (self, other) |
| } else { |
| (other, self) |
| }; |
| if small.len() > other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF { |
| // Small set is not much smaller than other set. |
| // Iterate both sets jointly, spotting matches along the way. |
| Intersection { |
| inner: IntersectionInner::Stitch { |
| a: small.iter(), |
| b: other.iter(), |
| }, |
| } |
| } else { |
| // Big difference in number of elements, or both sets are empty. |
| // Iterate the small set, searching for matches in the large set. |
| Intersection { |
| inner: IntersectionInner::Search { |
| small_iter: small.iter(), |
| large_set: other, |
| }, |
| } |
| } |
| } |
| |
| /// Visits the values representing the union, |
| /// i.e., all the values 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]); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn union<'a>(&'a self, other: &'a BTreeSet<T>) -> Union<'a, T> { |
| Union { |
| a: self.iter().peekable(), |
| b: other.iter().peekable(), |
| } |
| } |
| |
| /// Clears the set, removing all values. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::collections::BTreeSet; |
| /// |
| /// let mut v = BTreeSet::new(); |
| /// v.insert(1); |
| /// v.clear(); |
| /// assert!(v.is_empty()); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn clear(&mut self) { |
| self.map.clear() |
| } |
| |
| /// 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 |
| /// |
| /// ``` |
| /// 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); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool |
| where T: Borrow<Q>, |
| Q: Ord |
| { |
| self.map.contains_key(value) |
| } |
| |
| /// 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. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// 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); |
| /// ``` |
| #[stable(feature = "set_recovery", since = "1.9.0")] |
| pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T> |
| where T: Borrow<Q>, |
| Q: Ord |
| { |
| Recover::get(&self.map, value) |
| } |
| |
| /// 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<_> = [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); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn is_disjoint(&self, other: &BTreeSet<T>) -> bool { |
| self.intersection(other).next().is_none() |
| } |
| |
| /// Returns `true` if the set is a subset of another, |
| /// i.e., `other` contains at least all the values in `self`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// 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); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn is_subset(&self, other: &BTreeSet<T>) -> bool { |
| // Same result as self.difference(other).next().is_none() |
| // but the 3 paths below are faster (in order: hugely, 20%, 5%). |
| if self.len() > other.len() { |
| false |
| } else if self.len() > other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF { |
| // Self is not much smaller than other set. |
| // Stolen from TreeMap |
| let mut x = self.iter(); |
| let mut y = other.iter(); |
| let mut a = x.next(); |
| let mut b = y.next(); |
| while a.is_some() { |
| if b.is_none() { |
| return false; |
| } |
| |
| let a1 = a.unwrap(); |
| let b1 = b.unwrap(); |
| |
| match b1.cmp(a1) { |
| Less => (), |
| Greater => return false, |
| Equal => a = x.next(), |
| } |
| |
| b = y.next(); |
| } |
| true |
| } else { |
| // Big difference in number of elements, or both sets are empty. |
| // Iterate the small set, searching for matches in the large set. |
| for next in self { |
| if !other.contains(next) { |
| return false; |
| } |
| } |
| true |
| } |
| } |
| |
| /// Returns `true` if the set is a superset of another, |
| /// i.e., `self` contains at least all the values in `other`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// 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); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn is_superset(&self, other: &BTreeSet<T>) -> bool { |
| other.is_subset(self) |
| } |
| |
| /// 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. |
| /// |
| /// [module-level documentation]: index.html#insert-and-complex-keys |
| /// |
| /// # 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); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn insert(&mut self, value: T) -> bool { |
| self.map.insert(value, ()).is_none() |
| } |
| |
| /// Adds a value to the set, replacing the existing value, if any, that is equal to the given |
| /// one. Returns the replaced value. |
| /// |
| /// # 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); |
| /// ``` |
| #[stable(feature = "set_recovery", since = "1.9.0")] |
| pub fn replace(&mut self, value: T) -> Option<T> { |
| Recover::replace(&mut self.map, value) |
| } |
| |
| /// Removes a value from the set. Returns whether 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 |
| /// |
| /// ``` |
| /// use std::collections::BTreeSet; |
| /// |
| /// let mut set = BTreeSet::new(); |
| /// |
| /// set.insert(2); |
| /// assert_eq!(set.remove(&2), true); |
| /// assert_eq!(set.remove(&2), false); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool |
| where T: Borrow<Q>, |
| Q: Ord |
| { |
| self.map.remove(value).is_some() |
| } |
| |
| /// 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. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// 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); |
| /// ``` |
| #[stable(feature = "set_recovery", since = "1.9.0")] |
| pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T> |
| where T: Borrow<Q>, |
| Q: Ord |
| { |
| Recover::take(&mut self.map, value) |
| } |
| |
| /// 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)); |
| /// ``` |
| #[stable(feature = "btree_append", since = "1.11.0")] |
| pub fn append(&mut self, other: &mut Self) { |
| self.map.append(&mut other.map); |
| } |
| |
| /// Splits the collection into two at the given key. Returns everything after the given key, |
| /// including the key. |
| /// |
| /// # 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)); |
| /// ``` |
| #[stable(feature = "btree_split_off", since = "1.11.0")] |
| pub fn split_off<Q: ?Sized + Ord>(&mut self, key: &Q) -> Self where T: Borrow<Q> { |
| BTreeSet { map: self.map.split_off(key) } |
| } |
| } |
| |
| impl<T> BTreeSet<T> { |
| /// Gets an iterator that visits the values in the `BTreeSet` in ascending order. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// 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); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn iter(&self) -> Iter<'_, T> { |
| Iter { iter: self.map.keys() } |
| } |
| |
| /// 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); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn len(&self) -> usize { |
| self.map.len() |
| } |
| |
| /// 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()); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn is_empty(&self) -> bool { |
| self.len() == 0 |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T: Ord> FromIterator<T> for BTreeSet<T> { |
| fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> BTreeSet<T> { |
| let mut set = BTreeSet::new(); |
| set.extend(iter); |
| set |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> IntoIterator for BTreeSet<T> { |
| type Item = T; |
| type IntoIter = IntoIter<T>; |
| |
| /// Gets an iterator for moving out the `BTreeSet`'s contents. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::collections::BTreeSet; |
| /// |
| /// let set: BTreeSet<usize> = [1, 2, 3, 4].iter().cloned().collect(); |
| /// |
| /// let v: Vec<_> = set.into_iter().collect(); |
| /// assert_eq!(v, [1, 2, 3, 4]); |
| /// ``` |
| fn into_iter(self) -> IntoIter<T> { |
| IntoIter { iter: self.map.into_iter() } |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a, T> IntoIterator for &'a BTreeSet<T> { |
| type Item = &'a T; |
| type IntoIter = Iter<'a, T>; |
| |
| fn into_iter(self) -> Iter<'a, T> { |
| self.iter() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T: Ord> Extend<T> for BTreeSet<T> { |
| #[inline] |
| fn extend<Iter: IntoIterator<Item = T>>(&mut self, iter: Iter) { |
| iter.into_iter().for_each(move |elem| { |
| self.insert(elem); |
| }); |
| } |
| } |
| |
| #[stable(feature = "extend_ref", since = "1.2.0")] |
| impl<'a, T: 'a + Ord + Copy> Extend<&'a T> for BTreeSet<T> { |
| fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) { |
| self.extend(iter.into_iter().cloned()); |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T: Ord> Default for BTreeSet<T> { |
| /// Makes an empty `BTreeSet<T>` with a reasonable choice of B. |
| fn default() -> BTreeSet<T> { |
| BTreeSet::new() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T: Ord + Clone> Sub<&BTreeSet<T>> for &BTreeSet<T> { |
| type Output = BTreeSet<T>; |
| |
| /// Returns the difference of `self` and `rhs` as a new `BTreeSet<T>`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::collections::BTreeSet; |
| /// |
| /// let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect(); |
| /// let b: BTreeSet<_> = vec![3, 4, 5].into_iter().collect(); |
| /// |
| /// let result = &a - &b; |
| /// let result_vec: Vec<_> = result.into_iter().collect(); |
| /// assert_eq!(result_vec, [1, 2]); |
| /// ``` |
| fn sub(self, rhs: &BTreeSet<T>) -> BTreeSet<T> { |
| self.difference(rhs).cloned().collect() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T: Ord + Clone> BitXor<&BTreeSet<T>> for &BTreeSet<T> { |
| type Output = BTreeSet<T>; |
| |
| /// Returns the symmetric difference of `self` and `rhs` as a new `BTreeSet<T>`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::collections::BTreeSet; |
| /// |
| /// let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect(); |
| /// let b: BTreeSet<_> = vec![2, 3, 4].into_iter().collect(); |
| /// |
| /// let result = &a ^ &b; |
| /// let result_vec: Vec<_> = result.into_iter().collect(); |
| /// assert_eq!(result_vec, [1, 4]); |
| /// ``` |
| fn bitxor(self, rhs: &BTreeSet<T>) -> BTreeSet<T> { |
| self.symmetric_difference(rhs).cloned().collect() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T: Ord + Clone> BitAnd<&BTreeSet<T>> for &BTreeSet<T> { |
| type Output = BTreeSet<T>; |
| |
| /// Returns the intersection of `self` and `rhs` as a new `BTreeSet<T>`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::collections::BTreeSet; |
| /// |
| /// let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect(); |
| /// let b: BTreeSet<_> = vec![2, 3, 4].into_iter().collect(); |
| /// |
| /// let result = &a & &b; |
| /// let result_vec: Vec<_> = result.into_iter().collect(); |
| /// assert_eq!(result_vec, [2, 3]); |
| /// ``` |
| fn bitand(self, rhs: &BTreeSet<T>) -> BTreeSet<T> { |
| self.intersection(rhs).cloned().collect() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T: Ord + Clone> BitOr<&BTreeSet<T>> for &BTreeSet<T> { |
| type Output = BTreeSet<T>; |
| |
| /// Returns the union of `self` and `rhs` as a new `BTreeSet<T>`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::collections::BTreeSet; |
| /// |
| /// let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect(); |
| /// let b: BTreeSet<_> = vec![3, 4, 5].into_iter().collect(); |
| /// |
| /// let result = &a | &b; |
| /// let result_vec: Vec<_> = result.into_iter().collect(); |
| /// assert_eq!(result_vec, [1, 2, 3, 4, 5]); |
| /// ``` |
| fn bitor(self, rhs: &BTreeSet<T>) -> BTreeSet<T> { |
| self.union(rhs).cloned().collect() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T: Debug> Debug for BTreeSet<T> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.debug_set().entries(self.iter()).finish() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> Clone for Iter<'_, T> { |
| fn clone(&self) -> Self { |
| Iter { iter: self.iter.clone() } |
| } |
| } |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a, T> Iterator for Iter<'a, T> { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| self.iter.next() |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.iter.size_hint() |
| } |
| fn last(mut self) -> Option<&'a T> { |
| self.next_back() |
| } |
| } |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a, T> DoubleEndedIterator for Iter<'a, T> { |
| fn next_back(&mut self) -> Option<&'a T> { |
| self.iter.next_back() |
| } |
| } |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> ExactSizeIterator for Iter<'_, T> { |
| fn len(&self) -> usize { self.iter.len() } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl<T> FusedIterator for Iter<'_, T> {} |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> Iterator for IntoIter<T> { |
| type Item = T; |
| |
| fn next(&mut self) -> Option<T> { |
| self.iter.next().map(|(k, _)| k) |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.iter.size_hint() |
| } |
| } |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> DoubleEndedIterator for IntoIter<T> { |
| fn next_back(&mut self) -> Option<T> { |
| self.iter.next_back().map(|(k, _)| k) |
| } |
| } |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> ExactSizeIterator for IntoIter<T> { |
| fn len(&self) -> usize { self.iter.len() } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl<T> FusedIterator for IntoIter<T> {} |
| |
| #[stable(feature = "btree_range", since = "1.17.0")] |
| impl<T> Clone for Range<'_, T> { |
| fn clone(&self) -> Self { |
| Range { iter: self.iter.clone() } |
| } |
| } |
| |
| #[stable(feature = "btree_range", since = "1.17.0")] |
| impl<'a, T> Iterator for Range<'a, T> { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| self.iter.next().map(|(k, _)| k) |
| } |
| |
| fn last(mut self) -> Option<&'a T> { |
| self.next_back() |
| } |
| } |
| |
| #[stable(feature = "btree_range", since = "1.17.0")] |
| impl<'a, T> DoubleEndedIterator for Range<'a, T> { |
| fn next_back(&mut self) -> Option<&'a T> { |
| self.iter.next_back().map(|(k, _)| k) |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl<T> FusedIterator for Range<'_, T> {} |
| |
| /// Compares `x` and `y`, but return `short` if x is None and `long` if y is None |
| fn cmp_opt<T: Ord>(x: Option<&T>, y: Option<&T>, short: Ordering, long: Ordering) -> Ordering { |
| match (x, y) { |
| (None, _) => short, |
| (_, None) => long, |
| (Some(x1), Some(y1)) => x1.cmp(y1), |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> Clone for Difference<'_, T> { |
| fn clone(&self) -> Self { |
| Difference { |
| inner: match &self.inner { |
| DifferenceInner::Stitch { |
| self_iter, |
| other_iter, |
| } => DifferenceInner::Stitch { |
| self_iter: self_iter.clone(), |
| other_iter: other_iter.clone(), |
| }, |
| DifferenceInner::Search { |
| self_iter, |
| other_set, |
| } => DifferenceInner::Search { |
| self_iter: self_iter.clone(), |
| other_set, |
| }, |
| }, |
| } |
| } |
| } |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a, T: Ord> Iterator for Difference<'a, T> { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| match &mut self.inner { |
| DifferenceInner::Stitch { |
| self_iter, |
| other_iter, |
| } => { |
| let mut self_next = self_iter.next()?; |
| loop { |
| match other_iter |
| .peek() |
| .map_or(Less, |other_next| Ord::cmp(self_next, other_next)) |
| { |
| Less => return Some(self_next), |
| Equal => { |
| self_next = self_iter.next()?; |
| other_iter.next(); |
| } |
| Greater => { |
| other_iter.next(); |
| } |
| } |
| } |
| } |
| DifferenceInner::Search { |
| self_iter, |
| other_set, |
| } => loop { |
| let self_next = self_iter.next()?; |
| if !other_set.contains(&self_next) { |
| return Some(self_next); |
| } |
| }, |
| } |
| } |
| |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| let (self_len, other_len) = match &self.inner { |
| DifferenceInner::Stitch { |
| self_iter, |
| other_iter |
| } => (self_iter.len(), other_iter.len()), |
| DifferenceInner::Search { |
| self_iter, |
| other_set |
| } => (self_iter.len(), other_set.len()), |
| }; |
| (self_len.saturating_sub(other_len), Some(self_len)) |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl<T: Ord> FusedIterator for Difference<'_, T> {} |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> Clone for SymmetricDifference<'_, T> { |
| fn clone(&self) -> Self { |
| SymmetricDifference { |
| a: self.a.clone(), |
| b: self.b.clone(), |
| } |
| } |
| } |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a, T: Ord> Iterator for SymmetricDifference<'a, T> { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| loop { |
| match cmp_opt(self.a.peek(), self.b.peek(), Greater, Less) { |
| Less => return self.a.next(), |
| Equal => { |
| self.a.next(); |
| self.b.next(); |
| } |
| Greater => return self.b.next(), |
| } |
| } |
| } |
| |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| (0, Some(self.a.len() + self.b.len())) |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl<T: Ord> FusedIterator for SymmetricDifference<'_, T> {} |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> Clone for Intersection<'_, T> { |
| fn clone(&self) -> Self { |
| Intersection { |
| inner: match &self.inner { |
| IntersectionInner::Stitch { |
| a, |
| b, |
| } => IntersectionInner::Stitch { |
| a: a.clone(), |
| b: b.clone(), |
| }, |
| IntersectionInner::Search { |
| small_iter, |
| large_set, |
| } => IntersectionInner::Search { |
| small_iter: small_iter.clone(), |
| large_set, |
| }, |
| }, |
| } |
| } |
| } |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a, T: Ord> Iterator for Intersection<'a, T> { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| match &mut self.inner { |
| IntersectionInner::Stitch { |
| a, |
| b, |
| } => { |
| let mut a_next = a.next()?; |
| let mut b_next = b.next()?; |
| loop { |
| match Ord::cmp(a_next, b_next) { |
| Less => a_next = a.next()?, |
| Greater => b_next = b.next()?, |
| Equal => return Some(a_next), |
| } |
| } |
| } |
| IntersectionInner::Search { |
| small_iter, |
| large_set, |
| } => loop { |
| let small_next = small_iter.next()?; |
| if large_set.contains(&small_next) { |
| return Some(small_next); |
| } |
| }, |
| } |
| } |
| |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| let min_len = match &self.inner { |
| IntersectionInner::Stitch { a, b } => min(a.len(), b.len()), |
| IntersectionInner::Search { small_iter, .. } => small_iter.len(), |
| }; |
| (0, Some(min_len)) |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl<T: Ord> FusedIterator for Intersection<'_, T> {} |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<T> Clone for Union<'_, T> { |
| fn clone(&self) -> Self { |
| Union { |
| a: self.a.clone(), |
| b: self.b.clone(), |
| } |
| } |
| } |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a, T: Ord> Iterator for Union<'a, T> { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| match cmp_opt(self.a.peek(), self.b.peek(), Greater, Less) { |
| Less => self.a.next(), |
| Equal => { |
| self.b.next(); |
| self.a.next() |
| } |
| Greater => self.b.next(), |
| } |
| } |
| |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| let a_len = self.a.len(); |
| let b_len = self.b.len(); |
| (max(a_len, b_len), Some(a_len + b_len)) |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl<T: Ord> FusedIterator for Union<'_, T> {} |