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+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! An implementation of a set using a bit vector as an underlying
+//! representation for holding unsigned numerical elements.
+//!
+//! It should also be noted that the amount of storage necessary for holding a
+//! set of objects is proportional to the maximum of the objects when viewed
+//! as a `usize`.
+//!
+//! # Examples
+//!
+//! ```
+//! use bit_set::BitSet;
+//!
+//! // It's a regular set
+//! let mut s = BitSet::new();
+//! s.insert(0);
+//! s.insert(3);
+//! s.insert(7);
+//!
+//! s.remove(7);
+//!
+//! if !s.contains(7) {
+//! println!("There is no 7");
+//! }
+//!
+//! // Can initialize from a `BitVec`
+//! let other = BitSet::from_bytes(&[0b11010000]);
+//!
+//! s.union_with(&other);
+//!
+//! // Print 0, 1, 3 in some order
+//! for x in s.iter() {
+//! println!("{}", x);
+//! }
+//!
+//! // Can convert back to a `BitVec`
+//! let bv = s.into_bit_vec();
+//! assert!(bv[3]);
+//! ```
+
+#![no_std]
+#![cfg_attr(all(test, feature = "nightly"), feature(test))]
+extern crate bit_vec;
+#[cfg(all(test, feature = "nightly"))]
+extern crate rand;
+#[cfg(all(test, feature = "nightly"))]
+extern crate test;
+
+#[cfg(test)]
+#[macro_use]
+extern crate std;
+
+use bit_vec::{BitBlock, BitVec, Blocks};
+use core::cmp;
+use core::cmp::Ordering;
+use core::fmt;
+use core::hash;
+use core::iter::{self, Chain, Enumerate, FromIterator, Repeat, Skip, Take};
+
+type MatchWords<'a, B> = Chain<Enumerate<Blocks<'a, B>>, Skip<Take<Enumerate<Repeat<B>>>>>;
+
+/// Computes how many blocks are needed to store that many bits
+fn blocks_for_bits<B: BitBlock>(bits: usize) -> usize {
+ // If we want 17 bits, dividing by 32 will produce 0. So we add 1 to make sure we
+ // reserve enough. But if we want exactly a multiple of 32, this will actually allocate
+ // one too many. So we need to check if that's the case. We can do that by computing if
+ // bitwise AND by `32 - 1` is 0. But LLVM should be able to optimize the semantically
+ // superior modulo operator on a power of two to this.
+ //
+ // Note that we can technically avoid this branch with the expression
+ // `(nbits + BITS - 1) / 32::BITS`, but if nbits is almost usize::MAX this will overflow.
+ if bits % B::bits() == 0 {
+ bits / B::bits()
+ } else {
+ bits / B::bits() + 1
+ }
+}
+
+// Take two BitVec's, and return iterators of their words, where the shorter one
+// has been padded with 0's
+fn match_words<'a, 'b, B: BitBlock>(
+ a: &'a BitVec<B>,
+ b: &'b BitVec<B>,
+) -> (MatchWords<'a, B>, MatchWords<'b, B>) {
+ let a_len = a.storage().len();
+ let b_len = b.storage().len();
+
+ // have to uselessly pretend to pad the longer one for type matching
+ if a_len < b_len {
+ (
+ a.blocks()
+ .enumerate()
+ .chain(iter::repeat(B::zero()).enumerate().take(b_len).skip(a_len)),
+ b.blocks()
+ .enumerate()
+ .chain(iter::repeat(B::zero()).enumerate().take(0).skip(0)),
+ )
+ } else {
+ (
+ a.blocks()
+ .enumerate()
+ .chain(iter::repeat(B::zero()).enumerate().take(0).skip(0)),
+ b.blocks()
+ .enumerate()
+ .chain(iter::repeat(B::zero()).enumerate().take(a_len).skip(b_len)),
+ )
+ }
+}
+
+pub struct BitSet<B = u32> {
+ bit_vec: BitVec<B>,
+}
+
+impl<B: BitBlock> Clone for BitSet<B> {
+ fn clone(&self) -> Self {
+ BitSet {
+ bit_vec: self.bit_vec.clone(),
+ }
+ }
+
+ fn clone_from(&mut self, other: &Self) {
+ self.bit_vec.clone_from(&other.bit_vec);
+ }
+}
+
+impl<B: BitBlock> Default for BitSet<B> {
+ #[inline]
+ fn default() -> Self {
+ BitSet {
+ bit_vec: Default::default(),
+ }
+ }
+}
+
+impl<B: BitBlock> FromIterator<usize> for BitSet<B> {
+ fn from_iter<I: IntoIterator<Item = usize>>(iter: I) -> Self {
+ let mut ret = Self::default();
+ ret.extend(iter);
+ ret
+ }
+}
+
+impl<B: BitBlock> Extend<usize> for BitSet<B> {
+ #[inline]
+ fn extend<I: IntoIterator<Item = usize>>(&mut self, iter: I) {
+ for i in iter {
+ self.insert(i);
+ }
+ }
+}
+
+impl<B: BitBlock> PartialOrd for BitSet<B> {
+ #[inline]
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ self.iter().partial_cmp(other)
+ }
+}
+
+impl<B: BitBlock> Ord for BitSet<B> {
+ #[inline]
+ fn cmp(&self, other: &Self) -> Ordering {
+ self.iter().cmp(other)
+ }
+}
+
+impl<B: BitBlock> PartialEq for BitSet<B> {
+ #[inline]
+ fn eq(&self, other: &Self) -> bool {
+ self.iter().eq(other)
+ }
+}
+
+impl<B: BitBlock> Eq for BitSet<B> {}
+
+impl BitSet<u32> {
+ /// Creates a new empty `BitSet`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut s = BitSet::new();
+ /// ```
+ #[inline]
+ pub fn new() -> Self {
+ Self::default()
+ }
+
+ /// Creates a new `BitSet` with initially no contents, able to
+ /// hold `nbits` elements without resizing.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut s = BitSet::with_capacity(100);
+ /// assert!(s.capacity() >= 100);
+ /// ```
+ #[inline]
+ pub fn with_capacity(nbits: usize) -> Self {
+ let bit_vec = BitVec::from_elem(nbits, false);
+ Self::from_bit_vec(bit_vec)
+ }
+
+ /// Creates a new `BitSet` from the given bit vector.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// extern crate bit_vec;
+ /// extern crate bit_set;
+ ///
+ /// fn main() {
+ /// use bit_vec::BitVec;
+ /// use bit_set::BitSet;
+ ///
+ /// let bv = BitVec::from_bytes(&[0b01100000]);
+ /// let s = BitSet::from_bit_vec(bv);
+ ///
+ /// // Print 1, 2 in arbitrary order
+ /// for x in s.iter() {
+ /// println!("{}", x);
+ /// }
+ /// }
+ /// ```
+ #[inline]
+ pub fn from_bit_vec(bit_vec: BitVec) -> Self {
+ BitSet { bit_vec }
+ }
+
+ pub fn from_bytes(bytes: &[u8]) -> Self {
+ BitSet {
+ bit_vec: BitVec::from_bytes(bytes),
+ }
+ }
+}
+
+impl<B: BitBlock> BitSet<B> {
+ /// Returns the capacity in bits for this bit vector. Inserting any
+ /// element less than this amount will not trigger a resizing.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut s = BitSet::with_capacity(100);
+ /// assert!(s.capacity() >= 100);
+ /// ```
+ #[inline]
+ pub fn capacity(&self) -> usize {
+ self.bit_vec.capacity()
+ }
+
+ /// Reserves capacity for the given `BitSet` to contain `len` distinct elements. In the case
+ /// of `BitSet` this means reallocations will not occur as long as all inserted elements
+ /// are less than `len`.
+ ///
+ /// The collection may reserve more space to avoid frequent reallocations.
+ ///
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut s = BitSet::new();
+ /// s.reserve_len(10);
+ /// assert!(s.capacity() >= 10);
+ /// ```
+ pub fn reserve_len(&mut self, len: usize) {
+ let cur_len = self.bit_vec.len();
+ if len >= cur_len {
+ self.bit_vec.reserve(len - cur_len);
+ }
+ }
+
+ /// Reserves the minimum capacity for the given `BitSet` to contain `len` distinct elements.
+ /// In the case of `BitSet` this means reallocations will not occur as long as all inserted
+ /// elements are less than `len`.
+ ///
+ /// Note that the allocator may give the collection more space than it requests. Therefore
+ /// capacity can not be relied upon to be precisely minimal. Prefer `reserve_len` if future
+ /// insertions are expected.
+ ///
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut s = BitSet::new();
+ /// s.reserve_len_exact(10);
+ /// assert!(s.capacity() >= 10);
+ /// ```
+ pub fn reserve_len_exact(&mut self, len: usize) {
+ let cur_len = self.bit_vec.len();
+ if len >= cur_len {
+ self.bit_vec.reserve_exact(len - cur_len);
+ }
+ }
+
+ /// Consumes this set to return the underlying bit vector.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut s = BitSet::new();
+ /// s.insert(0);
+ /// s.insert(3);
+ ///
+ /// let bv = s.into_bit_vec();
+ /// assert!(bv[0]);
+ /// assert!(bv[3]);
+ /// ```
+ #[inline]
+ pub fn into_bit_vec(self) -> BitVec<B> {
+ self.bit_vec
+ }
+
+ /// Returns a reference to the underlying bit vector.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut s = BitSet::new();
+ /// s.insert(0);
+ ///
+ /// let bv = s.get_ref();
+ /// assert_eq!(bv[0], true);
+ /// ```
+ #[inline]
+ pub fn get_ref(&self) -> &BitVec<B> {
+ &self.bit_vec
+ }
+
+ #[inline]
+ fn other_op<F>(&mut self, other: &Self, mut f: F)
+ where
+ F: FnMut(B, B) -> B,
+ {
+ // Unwrap BitVecs
+ let self_bit_vec = &mut self.bit_vec;
+ let other_bit_vec = &other.bit_vec;
+
+ let self_len = self_bit_vec.len();
+ let other_len = other_bit_vec.len();
+
+ // Expand the vector if necessary
+ if self_len < other_len {
+ self_bit_vec.grow(other_len - self_len, false);
+ }
+
+ // virtually pad other with 0's for equal lengths
+ let other_words = {
+ let (_, result) = match_words(self_bit_vec, other_bit_vec);
+ result
+ };
+
+ // Apply values found in other
+ for (i, w) in other_words {
+ let old = self_bit_vec.storage()[i];
+ let new = f(old, w);
+ unsafe {
+ self_bit_vec.storage_mut()[i] = new;
+ }
+ }
+ }
+
+ /// Truncates the underlying vector to the least length required.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut s = BitSet::new();
+ /// s.insert(32183231);
+ /// s.remove(32183231);
+ ///
+ /// // Internal storage will probably be bigger than necessary
+ /// println!("old capacity: {}", s.capacity());
+ ///
+ /// // Now should be smaller
+ /// s.shrink_to_fit();
+ /// println!("new capacity: {}", s.capacity());
+ /// ```
+ #[inline]
+ pub fn shrink_to_fit(&mut self) {
+ let bit_vec = &mut self.bit_vec;
+ // Obtain original length
+ let old_len = bit_vec.storage().len();
+ // Obtain coarse trailing zero length
+ let n = bit_vec
+ .storage()
+ .iter()
+ .rev()
+ .take_while(|&&n| n == B::zero())
+ .count();
+ // Truncate away all empty trailing blocks, then shrink_to_fit
+ let trunc_len = old_len - n;
+ unsafe {
+ bit_vec.storage_mut().truncate(trunc_len);
+ bit_vec.set_len(trunc_len * B::bits());
+ bit_vec.shrink_to_fit();
+ }
+ }
+
+ /// Iterator over each usize stored in the `BitSet`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let s = BitSet::from_bytes(&[0b01001010]);
+ ///
+ /// // Print 1, 4, 6 in arbitrary order
+ /// for x in s.iter() {
+ /// println!("{}", x);
+ /// }
+ /// ```
+ #[inline]
+ pub fn iter(&self) -> Iter<B> {
+ Iter(BlockIter::from_blocks(self.bit_vec.blocks()))
+ }
+
+ /// Iterator over each usize stored in `self` union `other`.
+ /// See [union_with](#method.union_with) for an efficient in-place version.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let a = BitSet::from_bytes(&[0b01101000]);
+ /// let b = BitSet::from_bytes(&[0b10100000]);
+ ///
+ /// // Print 0, 1, 2, 4 in arbitrary order
+ /// for x in a.union(&b) {
+ /// println!("{}", x);
+ /// }
+ /// ```
+ #[inline]
+ pub fn union<'a>(&'a self, other: &'a Self) -> Union<'a, B> {
+ fn or<B: BitBlock>(w1: B, w2: B) -> B {
+ w1 | w2
+ }
+
+ Union(BlockIter::from_blocks(TwoBitPositions {
+ set: self.bit_vec.blocks(),
+ other: other.bit_vec.blocks(),
+ merge: or,
+ }))
+ }
+
+ /// Iterator over each usize stored in `self` intersect `other`.
+ /// See [intersect_with](#method.intersect_with) for an efficient in-place version.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let a = BitSet::from_bytes(&[0b01101000]);
+ /// let b = BitSet::from_bytes(&[0b10100000]);
+ ///
+ /// // Print 2
+ /// for x in a.intersection(&b) {
+ /// println!("{}", x);
+ /// }
+ /// ```
+ #[inline]
+ pub fn intersection<'a>(&'a self, other: &'a Self) -> Intersection<'a, B> {
+ fn bitand<B: BitBlock>(w1: B, w2: B) -> B {
+ w1 & w2
+ }
+ let min = cmp::min(self.bit_vec.len(), other.bit_vec.len());
+
+ Intersection(
+ BlockIter::from_blocks(TwoBitPositions {
+ set: self.bit_vec.blocks(),
+ other: other.bit_vec.blocks(),
+ merge: bitand,
+ })
+ .take(min),
+ )
+ }
+
+ /// Iterator over each usize stored in the `self` setminus `other`.
+ /// See [difference_with](#method.difference_with) for an efficient in-place version.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let a = BitSet::from_bytes(&[0b01101000]);
+ /// let b = BitSet::from_bytes(&[0b10100000]);
+ ///
+ /// // Print 1, 4 in arbitrary order
+ /// for x in a.difference(&b) {
+ /// println!("{}", x);
+ /// }
+ ///
+ /// // Note that difference is not symmetric,
+ /// // and `b - a` means something else.
+ /// // This prints 0
+ /// for x in b.difference(&a) {
+ /// println!("{}", x);
+ /// }
+ /// ```
+ #[inline]
+ pub fn difference<'a>(&'a self, other: &'a Self) -> Difference<'a, B> {
+ fn diff<B: BitBlock>(w1: B, w2: B) -> B {
+ w1 & !w2
+ }
+
+ Difference(BlockIter::from_blocks(TwoBitPositions {
+ set: self.bit_vec.blocks(),
+ other: other.bit_vec.blocks(),
+ merge: diff,
+ }))
+ }
+
+ /// Iterator over each usize stored in the symmetric difference of `self` and `other`.
+ /// See [symmetric_difference_with](#method.symmetric_difference_with) for
+ /// an efficient in-place version.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let a = BitSet::from_bytes(&[0b01101000]);
+ /// let b = BitSet::from_bytes(&[0b10100000]);
+ ///
+ /// // Print 0, 1, 4 in arbitrary order
+ /// for x in a.symmetric_difference(&b) {
+ /// println!("{}", x);
+ /// }
+ /// ```
+ #[inline]
+ pub fn symmetric_difference<'a>(&'a self, other: &'a Self) -> SymmetricDifference<'a, B> {
+ fn bitxor<B: BitBlock>(w1: B, w2: B) -> B {
+ w1 ^ w2
+ }
+
+ SymmetricDifference(BlockIter::from_blocks(TwoBitPositions {
+ set: self.bit_vec.blocks(),
+ other: other.bit_vec.blocks(),
+ merge: bitxor,
+ }))
+ }
+
+ /// Unions in-place with the specified other bit vector.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let a = 0b01101000;
+ /// let b = 0b10100000;
+ /// let res = 0b11101000;
+ ///
+ /// let mut a = BitSet::from_bytes(&[a]);
+ /// let b = BitSet::from_bytes(&[b]);
+ /// let res = BitSet::from_bytes(&[res]);
+ ///
+ /// a.union_with(&b);
+ /// assert_eq!(a, res);
+ /// ```
+ #[inline]
+ pub fn union_with(&mut self, other: &Self) {
+ self.other_op(other, |w1, w2| w1 | w2);
+ }
+
+ /// Intersects in-place with the specified other bit vector.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let a = 0b01101000;
+ /// let b = 0b10100000;
+ /// let res = 0b00100000;
+ ///
+ /// let mut a = BitSet::from_bytes(&[a]);
+ /// let b = BitSet::from_bytes(&[b]);
+ /// let res = BitSet::from_bytes(&[res]);
+ ///
+ /// a.intersect_with(&b);
+ /// assert_eq!(a, res);
+ /// ```
+ #[inline]
+ pub fn intersect_with(&mut self, other: &Self) {
+ self.other_op(other, |w1, w2| w1 & w2);
+ }
+
+ /// Makes this bit vector the difference with the specified other bit vector
+ /// in-place.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let a = 0b01101000;
+ /// let b = 0b10100000;
+ /// let a_b = 0b01001000; // a - b
+ /// let b_a = 0b10000000; // b - a
+ ///
+ /// let mut bva = BitSet::from_bytes(&[a]);
+ /// let bvb = BitSet::from_bytes(&[b]);
+ /// let bva_b = BitSet::from_bytes(&[a_b]);
+ /// let bvb_a = BitSet::from_bytes(&[b_a]);
+ ///
+ /// bva.difference_with(&bvb);
+ /// assert_eq!(bva, bva_b);
+ ///
+ /// let bva = BitSet::from_bytes(&[a]);
+ /// let mut bvb = BitSet::from_bytes(&[b]);
+ ///
+ /// bvb.difference_with(&bva);
+ /// assert_eq!(bvb, bvb_a);
+ /// ```
+ #[inline]
+ pub fn difference_with(&mut self, other: &Self) {
+ self.other_op(other, |w1, w2| w1 & !w2);
+ }
+
+ /// Makes this bit vector the symmetric difference with the specified other
+ /// bit vector in-place.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let a = 0b01101000;
+ /// let b = 0b10100000;
+ /// let res = 0b11001000;
+ ///
+ /// let mut a = BitSet::from_bytes(&[a]);
+ /// let b = BitSet::from_bytes(&[b]);
+ /// let res = BitSet::from_bytes(&[res]);
+ ///
+ /// a.symmetric_difference_with(&b);
+ /// assert_eq!(a, res);
+ /// ```
+ #[inline]
+ pub fn symmetric_difference_with(&mut self, other: &Self) {
+ self.other_op(other, |w1, w2| w1 ^ w2);
+ }
+
+ /*
+ /// Moves all elements from `other` into `Self`, leaving `other` empty.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut a = BitSet::new();
+ /// a.insert(2);
+ /// a.insert(6);
+ ///
+ /// let mut b = BitSet::new();
+ /// b.insert(1);
+ /// b.insert(3);
+ /// b.insert(6);
+ ///
+ /// a.append(&mut b);
+ ///
+ /// assert_eq!(a.len(), 4);
+ /// assert_eq!(b.len(), 0);
+ /// assert_eq!(a, BitSet::from_bytes(&[0b01110010]));
+ /// ```
+ pub fn append(&mut self, other: &mut Self) {
+ self.union_with(other);
+ other.clear();
+ }
+
+ /// Splits the `BitSet` into two at the given key including the key.
+ /// Retains the first part in-place while returning the second part.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bit_set::BitSet;
+ ///
+ /// let mut a = BitSet::new();
+ /// a.insert(2);
+ /// a.insert(6);
+ /// a.insert(1);
+ /// a.insert(3);
+ ///
+ /// let b = a.split_off(3);
+ ///
+ /// assert_eq!(a.len(), 2);
+ /// assert_eq!(b.len(), 2);
+ /// assert_eq!(a, BitSet::from_bytes(&[0b01100000]));
+ /// assert_eq!(b, BitSet::from_bytes(&[0b00010010]));
+ /// ```
+ pub fn split_off(&mut self, at: usize) -> Self {
+ let mut other = BitSet::new();
+
+ if at == 0 {
+ swap(self, &mut other);
+ return other;
+ } else if at >= self.bit_vec.len() {
+ return other;
+ }
+
+ // Calculate block and bit at which to split
+ let w = at / BITS;
+ let b = at % BITS;
+
+ // Pad `other` with `w` zero blocks,
+ // append `self`'s blocks in the range from `w` to the end to `other`
+ other.bit_vec.storage_mut().extend(repeat(0u32).take(w)
+ .chain(self.bit_vec.storage()[w..].iter().cloned()));
+ other.bit_vec.nbits = self.bit_vec.nbits;
+
+ if b > 0 {
+ other.bit_vec.storage_mut()[w] &= !0 << b;
+ }
+
+ // Sets `bit_vec.len()` and fixes the last block as well
+ self.bit_vec.truncate(at);
+
+ other
+ }
+ */
+
+ /// Returns the number of set bits in this set.
+ #[inline]
+ pub fn len(&self) -> usize {
+ self.bit_vec
+ .blocks()
+ .fold(0, |acc, n| acc + n.count_ones() as usize)
+ }
+
+ /// Returns whether there are no bits set in this set
+ #[inline]
+ pub fn is_empty(&self) -> bool {
+ self.bit_vec.none()
+ }
+
+ /// Clears all bits in this set
+ #[inline]
+ pub fn clear(&mut self) {
+ self.bit_vec.clear();
+ }
+
+ /// Returns `true` if this set contains the specified integer.
+ #[inline]
+ pub fn contains(&self, value: usize) -> bool {
+ let bit_vec = &self.bit_vec;
+ value < bit_vec.len() && bit_vec[value]
+ }
+
+ /// Returns `true` if the set has no elements in common with `other`.
+ /// This is equivalent to checking for an empty intersection.
+ #[inline]
+ pub fn is_disjoint(&self, other: &Self) -> bool {
+ self.intersection(other).next().is_none()
+ }
+
+ /// Returns `true` if the set is a subset of another.
+ #[inline]
+ pub fn is_subset(&self, other: &Self) -> bool {
+ let self_bit_vec = &self.bit_vec;
+ let other_bit_vec = &other.bit_vec;
+ let other_blocks = blocks_for_bits::<B>(other_bit_vec.len());
+
+ // Check that `self` intersect `other` is self
+ self_bit_vec.blocks().zip(other_bit_vec.blocks()).all(|(w1, w2)| w1 & w2 == w1) &&
+ // Make sure if `self` has any more blocks than `other`, they're all 0
+ self_bit_vec.blocks().skip(other_blocks).all(|w| w == B::zero())
+ }
+
+ /// Returns `true` if the set is a superset of another.
+ #[inline]
+ pub fn is_superset(&self, other: &Self) -> bool {
+ other.is_subset(self)
+ }
+
+ /// Adds a value to the set. Returns `true` if the value was not already
+ /// present in the set.
+ pub fn insert(&mut self, value: usize) -> bool {
+ if self.contains(value) {
+ return false;
+ }
+
+ // Ensure we have enough space to hold the new element
+ let len = self.bit_vec.len();
+ if value >= len {
+ self.bit_vec.grow(value - len + 1, false)
+ }
+
+ self.bit_vec.set(value, true);
+ true
+ }
+
+ /// Removes a value from the set. Returns `true` if the value was
+ /// present in the set.
+ pub fn remove(&mut self, value: usize) -> bool {
+ if !self.contains(value) {
+ return false;
+ }
+
+ self.bit_vec.set(value, false);
+
+ true
+ }
+}
+
+impl<B: BitBlock> fmt::Debug for BitSet<B> {
+ fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+ fmt.debug_set().entries(self).finish()
+ }
+}
+
+impl<B: BitBlock> hash::Hash for BitSet<B> {
+ fn hash<H: hash::Hasher>(&self, state: &mut H) {
+ for pos in self {
+ pos.hash(state);
+ }
+ }
+}
+
+#[derive(Clone)]
+struct BlockIter<T, B> {
+ head: B,
+ head_offset: usize,
+ tail: T,
+}
+
+impl<T, B: BitBlock> BlockIter<T, B>
+where
+ T: Iterator<Item = B>,
+{
+ fn from_blocks(mut blocks: T) -> BlockIter<T, B> {
+ let h = blocks.next().unwrap_or_else(B::zero);
+ BlockIter {
+ tail: blocks,
+ head: h,
+ head_offset: 0,
+ }
+ }
+}
+
+/// An iterator combining two `BitSet` iterators.
+#[derive(Clone)]
+struct TwoBitPositions<'a, B: 'a> {
+ set: Blocks<'a, B>,
+ other: Blocks<'a, B>,
+ merge: fn(B, B) -> B,
+}
+
+/// An iterator for `BitSet`.
+#[derive(Clone)]
+pub struct Iter<'a, B: 'a>(BlockIter<Blocks<'a, B>, B>);
+#[derive(Clone)]
+pub struct Union<'a, B: 'a>(BlockIter<TwoBitPositions<'a, B>, B>);
+#[derive(Clone)]
+pub struct Intersection<'a, B: 'a>(Take<BlockIter<TwoBitPositions<'a, B>, B>>);
+#[derive(Clone)]
+pub struct Difference<'a, B: 'a>(BlockIter<TwoBitPositions<'a, B>, B>);
+#[derive(Clone)]
+pub struct SymmetricDifference<'a, B: 'a>(BlockIter<TwoBitPositions<'a, B>, B>);
+
+impl<'a, T, B: BitBlock> Iterator for BlockIter<T, B>
+where
+ T: Iterator<Item = B>,
+{
+ type Item = usize;
+
+ fn next(&mut self) -> Option<usize> {
+ while self.head == B::zero() {
+ match self.tail.next() {
+ Some(w) => self.head = w,
+ None => return None,
+ }
+ self.head_offset += B::bits();
+ }
+
+ // from the current block, isolate the
+ // LSB and subtract 1, producing k:
+ // a block with a number of set bits
+ // equal to the index of the LSB
+ let k = (self.head & (!self.head + B::one())) - B::one();
+ // update block, removing the LSB
+ self.head = self.head & (self.head - B::one());
+ // return offset + (index of LSB)
+ Some(self.head_offset + (B::count_ones(k) as usize))
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ match self.tail.size_hint() {
+ (_, Some(h)) => (0, Some(1 + h * B::bits())),
+ _ => (0, None),
+ }
+ }
+}
+
+impl<'a, B: BitBlock> Iterator for TwoBitPositions<'a, B> {
+ type Item = B;
+
+ fn next(&mut self) -> Option<B> {
+ match (self.set.next(), self.other.next()) {
+ (Some(a), Some(b)) => Some((self.merge)(a, b)),
+ (Some(a), None) => Some((self.merge)(a, B::zero())),
+ (None, Some(b)) => Some((self.merge)(B::zero(), b)),
+ _ => None,
+ }
+ }
+
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ let (a, au) = self.set.size_hint();
+ let (b, bu) = self.other.size_hint();
+
+ let upper = match (au, bu) {
+ (Some(au), Some(bu)) => Some(cmp::max(au, bu)),
+ _ => None,
+ };
+
+ (cmp::max(a, b), upper)
+ }
+}
+
+impl<'a, B: BitBlock> Iterator for Iter<'a, B> {
+ type Item = usize;
+
+ #[inline]
+ fn next(&mut self) -> Option<usize> {
+ self.0.next()
+ }
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.0.size_hint()
+ }
+}
+
+impl<'a, B: BitBlock> Iterator for Union<'a, B> {
+ type Item = usize;
+
+ #[inline]
+ fn next(&mut self) -> Option<usize> {
+ self.0.next()
+ }
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.0.size_hint()
+ }
+}
+
+impl<'a, B: BitBlock> Iterator for Intersection<'a, B> {
+ type Item = usize;
+
+ #[inline]
+ fn next(&mut self) -> Option<usize> {
+ self.0.next()
+ }
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.0.size_hint()
+ }
+}
+
+impl<'a, B: BitBlock> Iterator for Difference<'a, B> {
+ type Item = usize;
+
+ #[inline]
+ fn next(&mut self) -> Option<usize> {
+ self.0.next()
+ }
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.0.size_hint()
+ }
+}
+
+impl<'a, B: BitBlock> Iterator for SymmetricDifference<'a, B> {
+ type Item = usize;
+
+ #[inline]
+ fn next(&mut self) -> Option<usize> {
+ self.0.next()
+ }
+ #[inline]
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.0.size_hint()
+ }
+}
+
+impl<'a, B: BitBlock> IntoIterator for &'a BitSet<B> {
+ type Item = usize;
+ type IntoIter = Iter<'a, B>;
+
+ fn into_iter(self) -> Iter<'a, B> {
+ self.iter()
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::BitSet;
+ use bit_vec::BitVec;
+ use std::cmp::Ordering::{Equal, Greater, Less};
+ use std::vec::Vec;
+
+ #[test]
+ fn test_bit_set_show() {
+ let mut s = BitSet::new();
+ s.insert(1);
+ s.insert(10);
+ s.insert(50);
+ s.insert(2);
+ assert_eq!("{1, 2, 10, 50}", format!("{:?}", s));
+ }
+
+ #[test]
+ fn test_bit_set_from_usizes() {
+ let usizes = vec![0, 2, 2, 3];
+ let a: BitSet = usizes.into_iter().collect();
+ let mut b = BitSet::new();
+ b.insert(0);
+ b.insert(2);
+ b.insert(3);
+ assert_eq!(a, b);
+ }
+
+ #[test]
+ fn test_bit_set_iterator() {
+ let usizes = vec![0, 2, 2, 3];
+ let bit_vec: BitSet = usizes.into_iter().collect();
+
+ let idxs: Vec<_> = bit_vec.iter().collect();
+ assert_eq!(idxs, [0, 2, 3]);
+
+ let long: BitSet = (0..10000).filter(|&n| n % 2 == 0).collect();
+ let real: Vec<_> = (0..10000 / 2).map(|x| x * 2).collect();
+
+ let idxs: Vec<_> = long.iter().collect();
+ assert_eq!(idxs, real);
+ }
+
+ #[test]
+ fn test_bit_set_frombit_vec_init() {
+ let bools = [true, false];
+ let lengths = [10, 64, 100];
+ for &b in &bools {
+ for &l in &lengths {
+ let bitset = BitSet::from_bit_vec(BitVec::from_elem(l, b));
+ assert_eq!(bitset.contains(1), b);
+ assert_eq!(bitset.contains(l - 1), b);
+ assert!(!bitset.contains(l));
+ }
+ }
+ }
+
+ #[test]
+ fn test_bit_vec_masking() {
+ let b = BitVec::from_elem(140, true);
+ let mut bs = BitSet::from_bit_vec(b);
+ assert!(bs.contains(139));
+ assert!(!bs.contains(140));
+ assert!(bs.insert(150));
+ assert!(!bs.contains(140));
+ assert!(!bs.contains(149));
+ assert!(bs.contains(150));
+ assert!(!bs.contains(151));
+ }
+
+ #[test]
+ fn test_bit_set_basic() {
+ let mut b = BitSet::new();
+ assert!(b.insert(3));
+ assert!(!b.insert(3));
+ assert!(b.contains(3));
+ assert!(b.insert(4));
+ assert!(!b.insert(4));
+ assert!(b.contains(3));
+ assert!(b.insert(400));
+ assert!(!b.insert(400));
+ assert!(b.contains(400));
+ assert_eq!(b.len(), 3);
+ }
+
+ #[test]
+ fn test_bit_set_intersection() {
+ let mut a = BitSet::new();
+ let mut b = BitSet::new();
+
+ assert!(a.insert(11));
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(77));
+ assert!(a.insert(103));
+ assert!(a.insert(5));
+
+ assert!(b.insert(2));
+ assert!(b.insert(11));
+ assert!(b.insert(77));
+ assert!(b.insert(5));
+ assert!(b.insert(3));
+
+ let expected = [3, 5, 11, 77];
+ let actual: Vec<_> = a.intersection(&b).collect();
+ assert_eq!(actual, expected);
+ }
+
+ #[test]
+ fn test_bit_set_difference() {
+ let mut a = BitSet::new();
+ let mut b = BitSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(200));
+ assert!(a.insert(500));
+
+ assert!(b.insert(3));
+ assert!(b.insert(200));
+
+ let expected = [1, 5, 500];
+ let actual: Vec<_> = a.difference(&b).collect();
+ assert_eq!(actual, expected);
+ }
+
+ #[test]
+ fn test_bit_set_symmetric_difference() {
+ let mut a = BitSet::new();
+ let mut b = BitSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+
+ assert!(b.insert(3));
+ assert!(b.insert(9));
+ assert!(b.insert(14));
+ assert!(b.insert(220));
+
+ let expected = [1, 5, 11, 14, 220];
+ let actual: Vec<_> = a.symmetric_difference(&b).collect();
+ assert_eq!(actual, expected);
+ }
+
+ #[test]
+ fn test_bit_set_union() {
+ let mut a = BitSet::new();
+ let mut b = BitSet::new();
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+ assert!(a.insert(160));
+ assert!(a.insert(19));
+ assert!(a.insert(24));
+ assert!(a.insert(200));
+
+ assert!(b.insert(1));
+ assert!(b.insert(5));
+ assert!(b.insert(9));
+ assert!(b.insert(13));
+ assert!(b.insert(19));
+
+ let expected = [1, 3, 5, 9, 11, 13, 19, 24, 160, 200];
+ let actual: Vec<_> = a.union(&b).collect();
+ assert_eq!(actual, expected);
+ }
+
+ #[test]
+ fn test_bit_set_subset() {
+ let mut set1 = BitSet::new();
+ let mut set2 = BitSet::new();
+
+ assert!(set1.is_subset(&set2)); // {} {}
+ set2.insert(100);
+ assert!(set1.is_subset(&set2)); // {} { 1 }
+ set2.insert(200);
+ assert!(set1.is_subset(&set2)); // {} { 1, 2 }
+ set1.insert(200);
+ assert!(set1.is_subset(&set2)); // { 2 } { 1, 2 }
+ set1.insert(300);
+ assert!(!set1.is_subset(&set2)); // { 2, 3 } { 1, 2 }
+ set2.insert(300);
+ assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3 }
+ set2.insert(400);
+ assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3, 4 }
+ set2.remove(100);
+ assert!(set1.is_subset(&set2)); // { 2, 3 } { 2, 3, 4 }
+ set2.remove(300);
+ assert!(!set1.is_subset(&set2)); // { 2, 3 } { 2, 4 }
+ set1.remove(300);
+ assert!(set1.is_subset(&set2)); // { 2 } { 2, 4 }
+ }
+
+ #[test]
+ fn test_bit_set_is_disjoint() {
+ let a = BitSet::from_bytes(&[0b10100010]);
+ let b = BitSet::from_bytes(&[0b01000000]);
+ let c = BitSet::new();
+ let d = BitSet::from_bytes(&[0b00110000]);
+
+ assert!(!a.is_disjoint(&d));
+ assert!(!d.is_disjoint(&a));
+
+ assert!(a.is_disjoint(&b));
+ assert!(a.is_disjoint(&c));
+ assert!(b.is_disjoint(&a));
+ assert!(b.is_disjoint(&c));
+ assert!(c.is_disjoint(&a));
+ assert!(c.is_disjoint(&b));
+ }
+
+ #[test]
+ fn test_bit_set_union_with() {
+ //a should grow to include larger elements
+ let mut a = BitSet::new();
+ a.insert(0);
+ let mut b = BitSet::new();
+ b.insert(5);
+ let expected = BitSet::from_bytes(&[0b10000100]);
+ a.union_with(&b);
+ assert_eq!(a, expected);
+
+ // Standard
+ let mut a = BitSet::from_bytes(&[0b10100010]);
+ let mut b = BitSet::from_bytes(&[0b01100010]);
+ let c = a.clone();
+ a.union_with(&b);
+ b.union_with(&c);
+ assert_eq!(a.len(), 4);
+ assert_eq!(b.len(), 4);
+ }
+
+ #[test]
+ fn test_bit_set_intersect_with() {
+ // Explicitly 0'ed bits
+ let mut a = BitSet::from_bytes(&[0b10100010]);
+ let mut b = BitSet::from_bytes(&[0b00000000]);
+ let c = a.clone();
+ a.intersect_with(&b);
+ b.intersect_with(&c);
+ assert!(a.is_empty());
+ assert!(b.is_empty());
+
+ // Uninitialized bits should behave like 0's
+ let mut a = BitSet::from_bytes(&[0b10100010]);
+ let mut b = BitSet::new();
+ let c = a.clone();
+ a.intersect_with(&b);
+ b.intersect_with(&c);
+ assert!(a.is_empty());
+ assert!(b.is_empty());
+
+ // Standard
+ let mut a = BitSet::from_bytes(&[0b10100010]);
+ let mut b = BitSet::from_bytes(&[0b01100010]);
+ let c = a.clone();
+ a.intersect_with(&b);
+ b.intersect_with(&c);
+ assert_eq!(a.len(), 2);
+ assert_eq!(b.len(), 2);
+ }
+
+ #[test]
+ fn test_bit_set_difference_with() {
+ // Explicitly 0'ed bits
+ let mut a = BitSet::from_bytes(&[0b00000000]);
+ let b = BitSet::from_bytes(&[0b10100010]);
+ a.difference_with(&b);
+ assert!(a.is_empty());
+
+ // Uninitialized bits should behave like 0's
+ let mut a = BitSet::new();
+ let b = BitSet::from_bytes(&[0b11111111]);
+ a.difference_with(&b);
+ assert!(a.is_empty());
+
+ // Standard
+ let mut a = BitSet::from_bytes(&[0b10100010]);
+ let mut b = BitSet::from_bytes(&[0b01100010]);
+ let c = a.clone();
+ a.difference_with(&b);
+ b.difference_with(&c);
+ assert_eq!(a.len(), 1);
+ assert_eq!(b.len(), 1);
+ }
+
+ #[test]
+ fn test_bit_set_symmetric_difference_with() {
+ //a should grow to include larger elements
+ let mut a = BitSet::new();
+ a.insert(0);
+ a.insert(1);
+ let mut b = BitSet::new();
+ b.insert(1);
+ b.insert(5);
+ let expected = BitSet::from_bytes(&[0b10000100]);
+ a.symmetric_difference_with(&b);
+ assert_eq!(a, expected);
+
+ let mut a = BitSet::from_bytes(&[0b10100010]);
+ let b = BitSet::new();
+ let c = a.clone();
+ a.symmetric_difference_with(&b);
+ assert_eq!(a, c);
+
+ // Standard
+ let mut a = BitSet::from_bytes(&[0b11100010]);
+ let mut b = BitSet::from_bytes(&[0b01101010]);
+ let c = a.clone();
+ a.symmetric_difference_with(&b);
+ b.symmetric_difference_with(&c);
+ assert_eq!(a.len(), 2);
+ assert_eq!(b.len(), 2);
+ }
+
+ #[test]
+ fn test_bit_set_eq() {
+ let a = BitSet::from_bytes(&[0b10100010]);
+ let b = BitSet::from_bytes(&[0b00000000]);
+ let c = BitSet::new();
+
+ assert!(a == a);
+ assert!(a != b);
+ assert!(a != c);
+ assert!(b == b);
+ assert!(b == c);
+ assert!(c == c);
+ }
+
+ #[test]
+ fn test_bit_set_cmp() {
+ let a = BitSet::from_bytes(&[0b10100010]);
+ let b = BitSet::from_bytes(&[0b00000000]);
+ let c = BitSet::new();
+
+ assert_eq!(a.cmp(&b), Greater);
+ assert_eq!(a.cmp(&c), Greater);
+ assert_eq!(b.cmp(&a), Less);
+ assert_eq!(b.cmp(&c), Equal);
+ assert_eq!(c.cmp(&a), Less);
+ assert_eq!(c.cmp(&b), Equal);
+ }
+
+ #[test]
+ fn test_bit_set_shrink_to_fit_new() {
+ // There was a strange bug where we refused to truncate to 0
+ // and this would end up actually growing the array in a way
+ // that (safely corrupted the state).
+ let mut a = BitSet::new();
+ assert_eq!(a.len(), 0);
+ assert_eq!(a.capacity(), 0);
+ a.shrink_to_fit();
+ assert_eq!(a.len(), 0);
+ assert_eq!(a.capacity(), 0);
+ assert!(!a.contains(1));
+ a.insert(3);
+ assert!(a.contains(3));
+ assert_eq!(a.len(), 1);
+ assert!(a.capacity() > 0);
+ a.shrink_to_fit();
+ assert!(a.contains(3));
+ assert_eq!(a.len(), 1);
+ assert!(a.capacity() > 0);
+ }
+
+ #[test]
+ fn test_bit_set_shrink_to_fit() {
+ let mut a = BitSet::new();
+ assert_eq!(a.len(), 0);
+ assert_eq!(a.capacity(), 0);
+ a.insert(259);
+ a.insert(98);
+ a.insert(3);
+ assert_eq!(a.len(), 3);
+ assert!(a.capacity() > 0);
+ assert!(!a.contains(1));
+ assert!(a.contains(259));
+ assert!(a.contains(98));
+ assert!(a.contains(3));
+
+ a.shrink_to_fit();
+ assert!(!a.contains(1));
+ assert!(a.contains(259));
+ assert!(a.contains(98));
+ assert!(a.contains(3));
+ assert_eq!(a.len(), 3);
+ assert!(a.capacity() > 0);
+
+ let old_cap = a.capacity();
+ assert!(a.remove(259));
+ a.shrink_to_fit();
+ assert!(a.capacity() < old_cap, "{} {}", a.capacity(), old_cap);
+ assert!(!a.contains(1));
+ assert!(!a.contains(259));
+ assert!(a.contains(98));
+ assert!(a.contains(3));
+ assert_eq!(a.len(), 2);
+
+ let old_cap2 = a.capacity();
+ a.clear();
+ assert_eq!(a.capacity(), old_cap2);
+ assert_eq!(a.len(), 0);
+ assert!(!a.contains(1));
+ assert!(!a.contains(259));
+ assert!(!a.contains(98));
+ assert!(!a.contains(3));
+
+ a.insert(512);
+ assert!(a.capacity() > 0);
+ assert_eq!(a.len(), 1);
+ assert!(a.contains(512));
+ assert!(!a.contains(1));
+ assert!(!a.contains(259));
+ assert!(!a.contains(98));
+ assert!(!a.contains(3));
+
+ a.remove(512);
+ a.shrink_to_fit();
+ assert_eq!(a.capacity(), 0);
+ assert_eq!(a.len(), 0);
+ assert!(!a.contains(512));
+ assert!(!a.contains(1));
+ assert!(!a.contains(259));
+ assert!(!a.contains(98));
+ assert!(!a.contains(3));
+ assert!(!a.contains(0));
+ }
+
+ #[test]
+ fn test_bit_vec_remove() {
+ let mut a = BitSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.remove(1));
+
+ assert!(a.insert(100));
+ assert!(a.remove(100));
+
+ assert!(a.insert(1000));
+ assert!(a.remove(1000));
+ a.shrink_to_fit();
+ }
+
+ #[test]
+ fn test_bit_vec_clone() {
+ let mut a = BitSet::new();
+
+ assert!(a.insert(1));
+ assert!(a.insert(100));
+ assert!(a.insert(1000));
+
+ let mut b = a.clone();
+
+ assert!(a == b);
+
+ assert!(b.remove(1));
+ assert!(a.contains(1));
+
+ assert!(a.remove(1000));
+ assert!(b.contains(1000));
+ }
+
+ /*
+ #[test]
+ fn test_bit_set_append() {
+ let mut a = BitSet::new();
+ a.insert(2);
+ a.insert(6);
+
+ let mut b = BitSet::new();
+ b.insert(1);
+ b.insert(3);
+ b.insert(6);
+
+ a.append(&mut b);
+
+ assert_eq!(a.len(), 4);
+ assert_eq!(b.len(), 0);
+ assert!(b.capacity() >= 6);
+
+ assert_eq!(a, BitSet::from_bytes(&[0b01110010]));
+ }
+
+ #[test]
+ fn test_bit_set_split_off() {
+ // Split at 0
+ let mut a = BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
+ 0b00110011, 0b01101011, 0b10101101]);
+
+ let b = a.split_off(0);
+
+ assert_eq!(a.len(), 0);
+ assert_eq!(b.len(), 21);
+
+ assert_eq!(b, BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
+ 0b00110011, 0b01101011, 0b10101101]);
+
+ // Split behind last element
+ let mut a = BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
+ 0b00110011, 0b01101011, 0b10101101]);
+
+ let b = a.split_off(50);
+
+ assert_eq!(a.len(), 21);
+ assert_eq!(b.len(), 0);
+
+ assert_eq!(a, BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
+ 0b00110011, 0b01101011, 0b10101101]));
+
+ // Split at arbitrary element
+ let mut a = BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
+ 0b00110011, 0b01101011, 0b10101101]);
+
+ let b = a.split_off(34);
+
+ assert_eq!(a.len(), 12);
+ assert_eq!(b.len(), 9);
+
+ assert_eq!(a, BitSet::from_bytes(&[0b10100000, 0b00010010, 0b10010010,
+ 0b00110011, 0b01000000]));
+ assert_eq!(b, BitSet::from_bytes(&[0, 0, 0, 0,
+ 0b00101011, 0b10101101]));
+ }
+ */
+}
+
+#[cfg(all(test, feature = "nightly"))]
+mod bench {
+ use super::BitSet;
+ use bit_vec::BitVec;
+ use rand::{thread_rng, Rng, ThreadRng};
+
+ use test::{black_box, Bencher};
+
+ const BENCH_BITS: usize = 1 << 14;
+ const BITS: usize = 32;
+
+ fn rng() -> ThreadRng {
+ thread_rng()
+ }
+
+ #[bench]
+ fn bench_bit_vecset_small(b: &mut Bencher) {
+ let mut r = rng();
+ let mut bit_vec = BitSet::new();
+ b.iter(|| {
+ for _ in 0..100 {
+ bit_vec.insert((r.next_u32() as usize) % BITS);
+ }
+ black_box(&bit_vec);
+ });
+ }
+
+ #[bench]
+ fn bench_bit_vecset_big(b: &mut Bencher) {
+ let mut r = rng();
+ let mut bit_vec = BitSet::new();
+ b.iter(|| {
+ for _ in 0..100 {
+ bit_vec.insert((r.next_u32() as usize) % BENCH_BITS);
+ }
+ black_box(&bit_vec);
+ });
+ }
+
+ #[bench]
+ fn bench_bit_vecset_iter(b: &mut Bencher) {
+ let bit_vec = BitSet::from_bit_vec(BitVec::from_fn(BENCH_BITS, |idx| idx % 3 == 0));
+ b.iter(|| {
+ let mut sum = 0;
+ for idx in &bit_vec {
+ sum += idx as usize;
+ }
+ sum
+ })
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 02:42:38 +0000