1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // FIXME(Gankro): BitVec and BitSet are very tightly coupled. Ideally (for
12 // maintenance), they should be in separate files/modules, with BitSet only
13 // using BitVec's public API. This will be hard for performance though, because
14 // `BitVec` will not want to leak its internal representation while its internal
15 // representation as `u32`s must be assumed for best performance.
17 // FIXME(tbu-): `BitVec`'s methods shouldn't be `union`, `intersection`, but
18 // rather `or` and `and`.
20 // (1) Be careful, most things can overflow here because the amount of bits in
21 // memory can overflow `usize`.
22 // (2) Make sure that the underlying vector has no excess length:
23 // E. g. `nbits == 16`, `storage.len() == 2` would be excess length,
24 // because the last word isn't used at all. This is important because some
25 // methods rely on it (for *CORRECTNESS*).
26 // (3) Make sure that the unused bits in the last word are zeroed out, again
27 // other methods rely on it for *CORRECTNESS*.
28 // (4) `BitSet` is tightly coupled with `BitVec`, so any changes you make in
29 // `BitVec` will need to be reflected in `BitSet`.
31 //! Collections implemented with bit vectors.
35 //! This is a simple example of the [Sieve of Eratosthenes][sieve]
36 //! which calculates prime numbers up to a given limit.
38 //! [sieve]: http://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
41 //! use std::collections::{BitSet, BitVec};
42 //! use std::num::Float;
45 //! let max_prime = 10000;
47 //! // Store the primes as a BitSet
49 //! // Assume all numbers are prime to begin, and then we
50 //! // cross off non-primes progressively
51 //! let mut bv = BitVec::from_elem(max_prime, true);
53 //! // Neither 0 nor 1 are prime
57 //! for i in iter::range_inclusive(2, (max_prime as f64).sqrt() as usize) {
58 //! // if i is a prime
60 //! // Mark all multiples of i as non-prime (any multiples below i * i
61 //! // will have been marked as non-prime previously)
62 //! for j in iter::range_step(i * i, max_prime, i) { bv.set(j, false) }
65 //! BitSet::from_bit_vec(bv)
68 //! // Simple primality tests below our max bound
69 //! let print_primes = 20;
70 //! print!("The primes below {} are: ", print_primes);
71 //! for x in 0..print_primes {
72 //! if primes.contains(&x) {
78 //! // We can manipulate the internal BitVec
79 //! let num_primes = primes.get_ref().iter().filter(|x| *x).count();
80 //! println!("There are {} primes below {}", num_primes, max_prime);
85 use core::cmp::Ordering;
87 use core::default::Default;
90 use core::iter::RandomAccessIterator;
91 use core::iter::{Chain, Enumerate, Repeat, Skip, Take, repeat, Cloned};
92 use core::iter::{self, FromIterator, IntoIterator};
96 use core::{u8, u32, usize};
97 use bit_set; //so meta
101 type Blocks<'a> = Cloned<slice::Iter<'a, u32>>;
102 type MutBlocks<'a> = slice::IterMut<'a, u32>;
103 type MatchWords<'a> = Chain<Enumerate<Blocks<'a>>, Skip<Take<Enumerate<Repeat<u32>>>>>;
105 fn reverse_bits(byte: u8) -> u8 {
107 for i in 0..u8::BITS {
108 result |= ((byte >> i) & 1) << (u8::BITS - 1 - i);
113 // Take two BitV's, and return iterators of their words, where the shorter one
114 // has been padded with 0's
115 fn match_words <'a,'b>(a: &'a BitVec, b: &'b BitVec) -> (MatchWords<'a>, MatchWords<'b>) {
116 let a_len = a.storage.len();
117 let b_len = b.storage.len();
119 // have to uselessly pretend to pad the longer one for type matching
121 (a.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(b_len).skip(a_len)),
122 b.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(0).skip(0)))
124 (a.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(0).skip(0)),
125 b.blocks().enumerate().chain(iter::repeat(0u32).enumerate().take(a_len).skip(b_len)))
129 static TRUE: bool = true;
130 static FALSE: bool = false;
132 /// The bitvector type.
137 /// use std::collections::BitVec;
139 /// let mut bv = BitVec::from_elem(10, false);
141 /// // insert all primes less than 10
146 /// println!("{:?}", bv);
147 /// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
149 /// // flip all values in bitvector, producing non-primes less than 10
151 /// println!("{:?}", bv);
152 /// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
154 /// // reset bitvector to empty
156 /// println!("{:?}", bv);
157 /// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
159 #[unstable(feature = "collections",
162 /// Internal representation of the bit vector
164 /// The number of valid bits in the internal representation
168 // FIXME(Gankro): NopeNopeNopeNopeNope (wait for IndexGet to be a thing)
169 impl Index<usize> for BitVec {
173 fn index(&self, i: &usize) -> &bool {
174 if self.get(*i).expect("index out of bounds") {
182 /// Computes how many blocks are needed to store that many bits
183 fn blocks_for_bits(bits: usize) -> usize {
184 // If we want 17 bits, dividing by 32 will produce 0. So we add 1 to make sure we
185 // reserve enough. But if we want exactly a multiple of 32, this will actually allocate
186 // one too many. So we need to check if that's the case. We can do that by computing if
187 // bitwise AND by `32 - 1` is 0. But LLVM should be able to optimize the semantically
188 // superior modulo operator on a power of two to this.
190 // Note that we can technically avoid this branch with the expression
191 // `(nbits + u32::BITS - 1) / 32::BITS`, but if nbits is almost usize::MAX this will overflow.
192 if bits % u32::BITS == 0 {
199 /// Computes the bitmask for the final word of the vector
200 fn mask_for_bits(bits: usize) -> u32 {
201 // Note especially that a perfect multiple of u32::BITS should mask all 1s.
202 !0u32 >> (u32::BITS - bits % u32::BITS) % u32::BITS
206 /// Applies the given operation to the blocks of self and other, and sets
207 /// self to be the result. This relies on the caller not to corrupt the
210 fn process<F>(&mut self, other: &BitVec, mut op: F) -> bool where F: FnMut(u32, u32) -> u32 {
211 assert_eq!(self.len(), other.len());
212 // This could theoretically be a `debug_assert!`.
213 assert_eq!(self.storage.len(), other.storage.len());
214 let mut changed = false;
215 for (a, b) in self.blocks_mut().zip(other.blocks()) {
225 /// Iterator over mutable refs to the underlying blocks of data.
226 fn blocks_mut(&mut self) -> MutBlocks {
228 self.storage.iter_mut()
231 /// Iterator over the underlying blocks of data
232 fn blocks(&self) -> Blocks {
234 self.storage.iter().cloned()
237 /// An operation might screw up the unused bits in the last block of the
238 /// `BitVec`. As per (3), it's assumed to be all 0s. This method fixes it up.
239 fn fix_last_block(&mut self) {
240 let extra_bits = self.len() % u32::BITS;
242 let mask = (1 << extra_bits) - 1;
243 let storage_len = self.storage.len();
244 self.storage[storage_len - 1] &= mask;
248 /// Creates an empty `BitVec`.
253 /// use std::collections::BitVec;
254 /// let mut bv = BitVec::new();
256 #[stable(feature = "rust1", since = "1.0.0")]
257 pub fn new() -> BitVec {
258 BitVec { storage: Vec::new(), nbits: 0 }
261 /// Creates a `BitVec` that holds `nbits` elements, setting each element
267 /// use std::collections::BitVec;
269 /// let mut bv = BitVec::from_elem(10, false);
270 /// assert_eq!(bv.len(), 10);
271 /// for x in bv.iter() {
272 /// assert_eq!(x, false);
275 pub fn from_elem(nbits: usize, bit: bool) -> BitVec {
276 let nblocks = blocks_for_bits(nbits);
277 let mut bit_vec = BitVec {
278 storage: repeat(if bit { !0u32 } else { 0u32 }).take(nblocks).collect(),
281 bit_vec.fix_last_block();
285 /// Constructs a new, empty `BitVec` with the specified capacity.
287 /// The bitvector will be able to hold at least `capacity` bits without
288 /// reallocating. If `capacity` is 0, it will not allocate.
290 /// It is important to note that this function does not specify the
291 /// *length* of the returned bitvector, but only the *capacity*.
292 #[stable(feature = "rust1", since = "1.0.0")]
293 pub fn with_capacity(nbits: usize) -> BitVec {
295 storage: Vec::with_capacity(blocks_for_bits(nbits)),
300 /// Transforms a byte-vector into a `BitVec`. Each byte becomes eight bits,
301 /// with the most significant bits of each byte coming first. Each
302 /// bit becomes `true` if equal to 1 or `false` if equal to 0.
307 /// use std::collections::BitVec;
309 /// let bv = BitVec::from_bytes(&[0b10100000, 0b00010010]);
310 /// assert!(bv.eq_vec(&[true, false, true, false,
311 /// false, false, false, false,
312 /// false, false, false, true,
313 /// false, false, true, false]));
315 pub fn from_bytes(bytes: &[u8]) -> BitVec {
316 let len = bytes.len().checked_mul(u8::BITS).expect("capacity overflow");
317 let mut bit_vec = BitVec::with_capacity(len);
318 let complete_words = bytes.len() / 4;
319 let extra_bytes = bytes.len() % 4;
323 for i in 0..complete_words {
324 bit_vec.storage.push(
325 ((reverse_bits(bytes[i * 4 + 0]) as u32) << 0) |
326 ((reverse_bits(bytes[i * 4 + 1]) as u32) << 8) |
327 ((reverse_bits(bytes[i * 4 + 2]) as u32) << 16) |
328 ((reverse_bits(bytes[i * 4 + 3]) as u32) << 24)
333 let mut last_word = 0u32;
334 for (i, &byte) in bytes[complete_words*4..].iter().enumerate() {
335 last_word |= (reverse_bits(byte) as u32) << (i * 8);
337 bit_vec.storage.push(last_word);
343 /// Creates a `BitVec` of the specified length where the value at each index
349 /// use std::collections::BitVec;
351 /// let bv = BitVec::from_fn(5, |i| { i % 2 == 0 });
352 /// assert!(bv.eq_vec(&[true, false, true, false, true]));
354 pub fn from_fn<F>(len: usize, mut f: F) -> BitVec where F: FnMut(usize) -> bool {
355 let mut bit_vec = BitVec::from_elem(len, false);
357 bit_vec.set(i, f(i));
362 /// Retrieves the value at index `i`, or `None` if the index is out of bounds.
367 /// use std::collections::BitVec;
369 /// let bv = BitVec::from_bytes(&[0b01100000]);
370 /// assert_eq!(bv.get(0), Some(false));
371 /// assert_eq!(bv.get(1), Some(true));
372 /// assert_eq!(bv.get(100), None);
374 /// // Can also use array indexing
375 /// assert_eq!(bv[1], true);
378 #[stable(feature = "rust1", since = "1.0.0")]
379 pub fn get(&self, i: usize) -> Option<bool> {
383 let w = i / u32::BITS;
384 let b = i % u32::BITS;
385 self.storage.get(w).map(|&block|
386 (block & (1 << b)) != 0
390 /// Sets the value of a bit at an index `i`.
394 /// Panics if `i` is out of bounds.
399 /// use std::collections::BitVec;
401 /// let mut bv = BitVec::from_elem(5, false);
403 /// assert_eq!(bv[3], true);
406 #[unstable(feature = "collections",
407 reason = "panic semantics are likely to change in the future")]
408 pub fn set(&mut self, i: usize, x: bool) {
409 assert!(i < self.nbits);
410 let w = i / u32::BITS;
411 let b = i % u32::BITS;
413 let val = if x { self.storage[w] | flag }
414 else { self.storage[w] & !flag };
415 self.storage[w] = val;
418 /// Sets all bits to 1.
423 /// use std::collections::BitVec;
425 /// let before = 0b01100000;
426 /// let after = 0b11111111;
428 /// let mut bv = BitVec::from_bytes(&[before]);
430 /// assert_eq!(bv, BitVec::from_bytes(&[after]));
433 pub fn set_all(&mut self) {
434 for w in &mut self.storage { *w = !0u32; }
435 self.fix_last_block();
443 /// use std::collections::BitVec;
445 /// let before = 0b01100000;
446 /// let after = 0b10011111;
448 /// let mut bv = BitVec::from_bytes(&[before]);
450 /// assert_eq!(bv, BitVec::from_bytes(&[after]));
453 pub fn negate(&mut self) {
454 for w in &mut self.storage { *w = !*w; }
455 self.fix_last_block();
458 /// Calculates the union of two bitvectors. This acts like the bitwise `or`
461 /// Sets `self` to the union of `self` and `other`. Both bitvectors must be
462 /// the same length. Returns `true` if `self` changed.
466 /// Panics if the bitvectors are of different lengths.
471 /// use std::collections::BitVec;
473 /// let a = 0b01100100;
474 /// let b = 0b01011010;
475 /// let res = 0b01111110;
477 /// let mut a = BitVec::from_bytes(&[a]);
478 /// let b = BitVec::from_bytes(&[b]);
480 /// assert!(a.union(&b));
481 /// assert_eq!(a, BitVec::from_bytes(&[res]));
484 pub fn union(&mut self, other: &BitVec) -> bool {
485 self.process(other, |w1, w2| w1 | w2)
488 /// Calculates the intersection of two bitvectors. This acts like the
489 /// bitwise `and` function.
491 /// Sets `self` to the intersection of `self` and `other`. Both bitvectors
492 /// must be the same length. Returns `true` if `self` changed.
496 /// Panics if the bitvectors are of different lengths.
501 /// use std::collections::BitVec;
503 /// let a = 0b01100100;
504 /// let b = 0b01011010;
505 /// let res = 0b01000000;
507 /// let mut a = BitVec::from_bytes(&[a]);
508 /// let b = BitVec::from_bytes(&[b]);
510 /// assert!(a.intersect(&b));
511 /// assert_eq!(a, BitVec::from_bytes(&[res]));
514 pub fn intersect(&mut self, other: &BitVec) -> bool {
515 self.process(other, |w1, w2| w1 & w2)
518 /// Calculates the difference between two bitvectors.
520 /// Sets each element of `self` to the value of that element minus the
521 /// element of `other` at the same index. Both bitvectors must be the same
522 /// length. Returns `true` if `self` changed.
526 /// Panics if the bitvectors are of different length.
531 /// use std::collections::BitVec;
533 /// let a = 0b01100100;
534 /// let b = 0b01011010;
535 /// let a_b = 0b00100100; // a - b
536 /// let b_a = 0b00011010; // b - a
538 /// let mut bva = BitVec::from_bytes(&[a]);
539 /// let bvb = BitVec::from_bytes(&[b]);
541 /// assert!(bva.difference(&bvb));
542 /// assert_eq!(bva, BitVec::from_bytes(&[a_b]));
544 /// let bva = BitVec::from_bytes(&[a]);
545 /// let mut bvb = BitVec::from_bytes(&[b]);
547 /// assert!(bvb.difference(&bva));
548 /// assert_eq!(bvb, BitVec::from_bytes(&[b_a]));
551 pub fn difference(&mut self, other: &BitVec) -> bool {
552 self.process(other, |w1, w2| w1 & !w2)
555 /// Returns `true` if all bits are 1.
560 /// use std::collections::BitVec;
562 /// let mut bv = BitVec::from_elem(5, true);
563 /// assert_eq!(bv.all(), true);
565 /// bv.set(1, false);
566 /// assert_eq!(bv.all(), false);
568 pub fn all(&self) -> bool {
569 let mut last_word = !0u32;
570 // Check that every block but the last is all-ones...
571 self.blocks().all(|elem| {
575 // and then check the last one has enough ones
576 }) && (last_word == mask_for_bits(self.nbits))
579 /// Returns an iterator over the elements of the vector in order.
584 /// use std::collections::BitVec;
586 /// let bv = BitVec::from_bytes(&[0b01110100, 0b10010010]);
587 /// assert_eq!(bv.iter().filter(|x| *x).count(), 7);
590 #[stable(feature = "rust1", since = "1.0.0")]
591 pub fn iter(&self) -> Iter {
592 Iter { bit_vec: self, next_idx: 0, end_idx: self.nbits }
595 /// Returns `true` if all bits are 0.
600 /// use std::collections::BitVec;
602 /// let mut bv = BitVec::from_elem(10, false);
603 /// assert_eq!(bv.none(), true);
606 /// assert_eq!(bv.none(), false);
608 pub fn none(&self) -> bool {
609 self.blocks().all(|w| w == 0)
612 /// Returns `true` if any bit is 1.
617 /// use std::collections::BitVec;
619 /// let mut bv = BitVec::from_elem(10, false);
620 /// assert_eq!(bv.any(), false);
623 /// assert_eq!(bv.any(), true);
626 pub fn any(&self) -> bool {
630 /// Organises the bits into bytes, such that the first bit in the
631 /// `BitVec` becomes the high-order bit of the first byte. If the
632 /// size of the `BitVec` is not a multiple of eight then trailing bits
633 /// will be filled-in with `false`.
638 /// use std::collections::BitVec;
640 /// let mut bv = BitVec::from_elem(3, true);
641 /// bv.set(1, false);
643 /// assert_eq!(bv.to_bytes(), vec!(0b10100000));
645 /// let mut bv = BitVec::from_elem(9, false);
649 /// assert_eq!(bv.to_bytes(), vec!(0b00100000, 0b10000000));
651 pub fn to_bytes(&self) -> Vec<u8> {
652 fn bit(bit_vec: &BitVec, byte: usize, bit: usize) -> u8 {
653 let offset = byte * 8 + bit;
654 if offset >= bit_vec.nbits {
657 (bit_vec[offset] as u8) << (7 - bit)
661 let len = self.nbits/8 +
662 if self.nbits % 8 == 0 { 0 } else { 1 };
675 /// Compares a `BitVec` to a slice of `bool`s.
676 /// Both the `BitVec` and slice must have the same length.
680 /// Panics if the `BitVec` and slice are of different length.
685 /// use std::collections::BitVec;
687 /// let bv = BitVec::from_bytes(&[0b10100000]);
689 /// assert!(bv.eq_vec(&[true, false, true, false,
690 /// false, false, false, false]));
692 pub fn eq_vec(&self, v: &[bool]) -> bool {
693 assert_eq!(self.nbits, v.len());
694 iter::order::eq(self.iter(), v.iter().cloned())
697 /// Shortens a `BitVec`, dropping excess elements.
699 /// If `len` is greater than the vector's current length, this has no
705 /// use std::collections::BitVec;
707 /// let mut bv = BitVec::from_bytes(&[0b01001011]);
709 /// assert!(bv.eq_vec(&[false, true]));
711 #[stable(feature = "rust1", since = "1.0.0")]
712 pub fn truncate(&mut self, len: usize) {
713 if len < self.len() {
716 self.storage.truncate(blocks_for_bits(len));
717 self.fix_last_block();
721 /// Reserves capacity for at least `additional` more bits to be inserted in the given
722 /// `BitVec`. The collection may reserve more space to avoid frequent reallocations.
726 /// Panics if the new capacity overflows `usize`.
731 /// use std::collections::BitVec;
733 /// let mut bv = BitVec::from_elem(3, false);
735 /// assert_eq!(bv.len(), 3);
736 /// assert!(bv.capacity() >= 13);
738 #[stable(feature = "rust1", since = "1.0.0")]
739 pub fn reserve(&mut self, additional: usize) {
740 let desired_cap = self.len().checked_add(additional).expect("capacity overflow");
741 let storage_len = self.storage.len();
742 if desired_cap > self.capacity() {
743 self.storage.reserve(blocks_for_bits(desired_cap) - storage_len);
747 /// Reserves the minimum capacity for exactly `additional` more bits to be inserted in the
748 /// given `BitVec`. Does nothing if the capacity is already sufficient.
750 /// Note that the allocator may give the collection more space than it requests. Therefore
751 /// capacity can not be relied upon to be precisely minimal. Prefer `reserve` if future
752 /// insertions are expected.
756 /// Panics if the new capacity overflows `usize`.
761 /// use std::collections::BitVec;
763 /// let mut bv = BitVec::from_elem(3, false);
765 /// assert_eq!(bv.len(), 3);
766 /// assert!(bv.capacity() >= 13);
768 #[stable(feature = "rust1", since = "1.0.0")]
769 pub fn reserve_exact(&mut self, additional: usize) {
770 let desired_cap = self.len().checked_add(additional).expect("capacity overflow");
771 let storage_len = self.storage.len();
772 if desired_cap > self.capacity() {
773 self.storage.reserve_exact(blocks_for_bits(desired_cap) - storage_len);
777 /// Returns the capacity in bits for this bit vector. Inserting any
778 /// element less than this amount will not trigger a resizing.
783 /// use std::collections::BitVec;
785 /// let mut bv = BitVec::new();
787 /// assert!(bv.capacity() >= 10);
790 #[stable(feature = "rust1", since = "1.0.0")]
791 pub fn capacity(&self) -> usize {
792 self.storage.capacity().checked_mul(u32::BITS).unwrap_or(usize::MAX)
795 /// Grows the `BitVec` in-place, adding `n` copies of `value` to the `BitVec`.
799 /// Panics if the new len overflows a `usize`.
804 /// use std::collections::BitVec;
806 /// let mut bv = BitVec::from_bytes(&[0b01001011]);
807 /// bv.grow(2, true);
808 /// assert_eq!(bv.len(), 10);
809 /// assert_eq!(bv.to_bytes(), vec!(0b01001011, 0b11000000));
811 pub fn grow(&mut self, n: usize, value: bool) {
812 // Note: we just bulk set all the bits in the last word in this fn in multiple places
813 // which is technically wrong if not all of these bits are to be used. However, at the end
814 // of this fn we call `fix_last_block` at the end of this fn, which should fix this.
816 let new_nbits = self.nbits.checked_add(n).expect("capacity overflow");
817 let new_nblocks = blocks_for_bits(new_nbits);
818 let full_value = if value { !0 } else { 0 };
820 // Correct the old tail word, setting or clearing formerly unused bits
821 let old_last_word = blocks_for_bits(self.nbits) - 1;
822 if self.nbits % u32::BITS > 0 {
823 let mask = mask_for_bits(self.nbits);
825 self.storage[old_last_word] |= !mask;
827 // Extra bits are already zero by invariant.
831 // Fill in words after the old tail word
832 let stop_idx = cmp::min(self.storage.len(), new_nblocks);
833 for idx in old_last_word + 1..stop_idx {
834 self.storage[idx] = full_value;
837 // Allocate new words, if needed
838 if new_nblocks > self.storage.len() {
839 let to_add = new_nblocks - self.storage.len();
840 self.storage.extend(repeat(full_value).take(to_add));
843 // Adjust internal bit count
844 self.nbits = new_nbits;
846 self.fix_last_block();
849 /// Removes the last bit from the BitVec, and returns it. Returns None if the BitVec is empty.
854 /// use std::collections::BitVec;
856 /// let mut bv = BitVec::from_bytes(&[0b01001001]);
857 /// assert_eq!(bv.pop(), Some(true));
858 /// assert_eq!(bv.pop(), Some(false));
859 /// assert_eq!(bv.len(), 6);
861 #[stable(feature = "rust1", since = "1.0.0")]
862 pub fn pop(&mut self) -> Option<bool> {
866 let i = self.nbits - 1;
871 if self.nbits % u32::BITS == 0 {
879 /// Pushes a `bool` onto the end.
884 /// use std::collections::BitVec;
886 /// let mut bv = BitVec::new();
889 /// assert!(bv.eq_vec(&[true, false]));
891 #[stable(feature = "rust1", since = "1.0.0")]
892 pub fn push(&mut self, elem: bool) {
893 if self.nbits % u32::BITS == 0 {
894 self.storage.push(0);
896 let insert_pos = self.nbits;
897 self.nbits = self.nbits.checked_add(1).expect("Capacity overflow");
898 self.set(insert_pos, elem);
901 /// Return the total number of bits in this vector
903 #[stable(feature = "rust1", since = "1.0.0")]
904 pub fn len(&self) -> usize { self.nbits }
906 /// Returns true if there are no bits in this vector
908 #[stable(feature = "rust1", since = "1.0.0")]
909 pub fn is_empty(&self) -> bool { self.len() == 0 }
911 /// Clears all bits in this vector.
913 #[stable(feature = "rust1", since = "1.0.0")]
914 pub fn clear(&mut self) {
915 for w in &mut self.storage { *w = 0u32; }
919 #[stable(feature = "rust1", since = "1.0.0")]
920 impl Default for BitVec {
922 fn default() -> BitVec { BitVec::new() }
925 #[stable(feature = "rust1", since = "1.0.0")]
926 impl FromIterator<bool> for BitVec {
927 fn from_iter<I: IntoIterator<Item=bool>>(iter: I) -> BitVec {
928 let mut ret = BitVec::new();
934 #[stable(feature = "rust1", since = "1.0.0")]
935 impl Extend<bool> for BitVec {
937 fn extend<I: IntoIterator<Item=bool>>(&mut self, iterable: I) {
938 let iterator = iterable.into_iter();
939 let (min, _) = iterator.size_hint();
941 for element in iterator {
947 #[stable(feature = "rust1", since = "1.0.0")]
948 impl Clone for BitVec {
950 fn clone(&self) -> BitVec {
951 BitVec { storage: self.storage.clone(), nbits: self.nbits }
955 fn clone_from(&mut self, source: &BitVec) {
956 self.nbits = source.nbits;
957 self.storage.clone_from(&source.storage);
961 #[stable(feature = "rust1", since = "1.0.0")]
962 impl PartialOrd for BitVec {
964 fn partial_cmp(&self, other: &BitVec) -> Option<Ordering> {
965 iter::order::partial_cmp(self.iter(), other.iter())
969 #[stable(feature = "rust1", since = "1.0.0")]
970 impl Ord for BitVec {
972 fn cmp(&self, other: &BitVec) -> Ordering {
973 iter::order::cmp(self.iter(), other.iter())
977 #[stable(feature = "rust1", since = "1.0.0")]
978 impl fmt::Debug for BitVec {
979 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
981 try!(write!(fmt, "{}", if bit { 1u32 } else { 0u32 }));
987 #[stable(feature = "rust1", since = "1.0.0")]
989 impl<S: hash::Writer + hash::Hasher> hash::Hash<S> for BitVec {
990 fn hash(&self, state: &mut S) {
991 self.nbits.hash(state);
992 for elem in self.blocks() {
997 #[stable(feature = "rust1", since = "1.0.0")]
999 impl hash::Hash for BitVec {
1000 fn hash<H: hash::Hasher>(&self, state: &mut H) {
1001 self.nbits.hash(state);
1002 for elem in self.blocks() {
1008 #[stable(feature = "rust1", since = "1.0.0")]
1009 impl cmp::PartialEq for BitVec {
1011 fn eq(&self, other: &BitVec) -> bool {
1012 if self.nbits != other.nbits {
1015 self.blocks().zip(other.blocks()).all(|(w1, w2)| w1 == w2)
1019 #[stable(feature = "rust1", since = "1.0.0")]
1020 impl cmp::Eq for BitVec {}
1022 /// An iterator for `BitVec`.
1023 #[stable(feature = "rust1", since = "1.0.0")]
1025 pub struct Iter<'a> {
1026 bit_vec: &'a BitVec,
1031 #[stable(feature = "rust1", since = "1.0.0")]
1032 impl<'a> Iterator for Iter<'a> {
1036 fn next(&mut self) -> Option<bool> {
1037 if self.next_idx != self.end_idx {
1038 let idx = self.next_idx;
1040 Some(self.bit_vec[idx])
1046 fn size_hint(&self) -> (usize, Option<usize>) {
1047 let rem = self.end_idx - self.next_idx;
1052 #[stable(feature = "rust1", since = "1.0.0")]
1053 impl<'a> DoubleEndedIterator for Iter<'a> {
1055 fn next_back(&mut self) -> Option<bool> {
1056 if self.next_idx != self.end_idx {
1058 Some(self.bit_vec[self.end_idx])
1065 #[stable(feature = "rust1", since = "1.0.0")]
1066 impl<'a> ExactSizeIterator for Iter<'a> {}
1068 #[stable(feature = "rust1", since = "1.0.0")]
1069 impl<'a> RandomAccessIterator for Iter<'a> {
1071 fn indexable(&self) -> usize {
1072 self.end_idx - self.next_idx
1076 fn idx(&mut self, index: usize) -> Option<bool> {
1077 if index >= self.indexable() {
1080 Some(self.bit_vec[index])
1085 #[stable(feature = "rust1", since = "1.0.0")]
1086 impl<'a> IntoIterator for &'a BitVec {
1088 type IntoIter = Iter<'a>;
1090 fn into_iter(self) -> Iter<'a> {
1095 /// An implementation of a set using a bit vector as an underlying
1096 /// representation for holding unsigned numerical elements.
1098 /// It should also be noted that the amount of storage necessary for holding a
1099 /// set of objects is proportional to the maximum of the objects when viewed
1105 /// use std::collections::{BitSet, BitVec};
1107 /// // It's a regular set
1108 /// let mut s = BitSet::new();
1115 /// if !s.contains(&7) {
1116 /// println!("There is no 7");
1119 /// // Can initialize from a `BitVec`
1120 /// let other = BitSet::from_bit_vec(BitVec::from_bytes(&[0b11010000]));
1122 /// s.union_with(&other);
1124 /// // Print 0, 1, 3 in some order
1125 /// for x in s.iter() {
1126 /// println!("{}", x);
1129 /// // Can convert back to a `BitVec`
1130 /// let bv: BitVec = s.into_bit_vec();
1134 #[unstable(feature = "collections",
1135 reason = "RFC 509")]
1140 #[stable(feature = "rust1", since = "1.0.0")]
1141 impl Default for BitSet {
1143 fn default() -> BitSet { BitSet::new() }
1146 #[stable(feature = "rust1", since = "1.0.0")]
1147 impl FromIterator<usize> for BitSet {
1148 fn from_iter<I: IntoIterator<Item=usize>>(iter: I) -> BitSet {
1149 let mut ret = BitSet::new();
1155 #[stable(feature = "rust1", since = "1.0.0")]
1156 impl Extend<usize> for BitSet {
1158 fn extend<I: IntoIterator<Item=usize>>(&mut self, iter: I) {
1165 #[stable(feature = "rust1", since = "1.0.0")]
1166 impl PartialOrd for BitSet {
1168 fn partial_cmp(&self, other: &BitSet) -> Option<Ordering> {
1169 let (a_iter, b_iter) = match_words(self.get_ref(), other.get_ref());
1170 iter::order::partial_cmp(a_iter, b_iter)
1174 #[stable(feature = "rust1", since = "1.0.0")]
1175 impl Ord for BitSet {
1177 fn cmp(&self, other: &BitSet) -> Ordering {
1178 let (a_iter, b_iter) = match_words(self.get_ref(), other.get_ref());
1179 iter::order::cmp(a_iter, b_iter)
1183 #[stable(feature = "rust1", since = "1.0.0")]
1184 impl cmp::PartialEq for BitSet {
1186 fn eq(&self, other: &BitSet) -> bool {
1187 let (a_iter, b_iter) = match_words(self.get_ref(), other.get_ref());
1188 iter::order::eq(a_iter, b_iter)
1192 #[stable(feature = "rust1", since = "1.0.0")]
1193 impl cmp::Eq for BitSet {}
1196 /// Creates a new empty `BitSet`.
1201 /// use std::collections::BitSet;
1203 /// let mut s = BitSet::new();
1206 #[stable(feature = "rust1", since = "1.0.0")]
1207 pub fn new() -> BitSet {
1208 BitSet { bit_vec: BitVec::new() }
1211 /// Creates a new `BitSet` with initially no contents, able to
1212 /// hold `nbits` elements without resizing.
1217 /// use std::collections::BitSet;
1219 /// let mut s = BitSet::with_capacity(100);
1220 /// assert!(s.capacity() >= 100);
1223 #[stable(feature = "rust1", since = "1.0.0")]
1224 pub fn with_capacity(nbits: usize) -> BitSet {
1225 let bit_vec = BitVec::from_elem(nbits, false);
1226 BitSet::from_bit_vec(bit_vec)
1229 /// Creates a new `BitSet` from the given bit vector.
1234 /// use std::collections::{BitVec, BitSet};
1236 /// let bv = BitVec::from_bytes(&[0b01100000]);
1237 /// let s = BitSet::from_bit_vec(bv);
1239 /// // Print 1, 2 in arbitrary order
1240 /// for x in s.iter() {
1241 /// println!("{}", x);
1245 pub fn from_bit_vec(bit_vec: BitVec) -> BitSet {
1246 BitSet { bit_vec: bit_vec }
1249 /// Deprecated: use `from_bit_vec`.
1251 #[deprecated(since = "1.0.0", reason = "renamed to from_bit_vec")]
1252 #[unstable(feature = "collections")]
1253 pub fn from_bitv(bit_vec: BitVec) -> BitSet {
1254 BitSet { bit_vec: bit_vec }
1257 /// Returns the capacity in bits for this bit vector. Inserting any
1258 /// element less than this amount will not trigger a resizing.
1263 /// use std::collections::BitSet;
1265 /// let mut s = BitSet::with_capacity(100);
1266 /// assert!(s.capacity() >= 100);
1269 #[stable(feature = "rust1", since = "1.0.0")]
1270 pub fn capacity(&self) -> usize {
1271 self.bit_vec.capacity()
1274 /// Reserves capacity for the given `BitSet` to contain `len` distinct elements. In the case
1275 /// of `BitSet` this means reallocations will not occur as long as all inserted elements
1276 /// are less than `len`.
1278 /// The collection may reserve more space to avoid frequent reallocations.
1284 /// use std::collections::BitSet;
1286 /// let mut s = BitSet::new();
1287 /// s.reserve_len(10);
1288 /// assert!(s.capacity() >= 10);
1290 #[stable(feature = "rust1", since = "1.0.0")]
1291 pub fn reserve_len(&mut self, len: usize) {
1292 let cur_len = self.bit_vec.len();
1294 self.bit_vec.reserve(len - cur_len);
1298 /// Reserves the minimum capacity for the given `BitSet` to contain `len` distinct elements.
1299 /// In the case of `BitSet` this means reallocations will not occur as long as all inserted
1300 /// elements are less than `len`.
1302 /// Note that the allocator may give the collection more space than it requests. Therefore
1303 /// capacity can not be relied upon to be precisely minimal. Prefer `reserve_len` if future
1304 /// insertions are expected.
1310 /// use std::collections::BitSet;
1312 /// let mut s = BitSet::new();
1313 /// s.reserve_len_exact(10);
1314 /// assert!(s.capacity() >= 10);
1316 #[stable(feature = "rust1", since = "1.0.0")]
1317 pub fn reserve_len_exact(&mut self, len: usize) {
1318 let cur_len = self.bit_vec.len();
1320 self.bit_vec.reserve_exact(len - cur_len);
1325 /// Consumes this set to return the underlying bit vector.
1330 /// use std::collections::BitSet;
1332 /// let mut s = BitSet::new();
1336 /// let bv = s.into_bit_vec();
1341 pub fn into_bit_vec(self) -> BitVec {
1345 /// Returns a reference to the underlying bit vector.
1350 /// use std::collections::BitSet;
1352 /// let mut s = BitSet::new();
1355 /// let bv = s.get_ref();
1356 /// assert_eq!(bv[0], true);
1359 pub fn get_ref(&self) -> &BitVec {
1364 fn other_op<F>(&mut self, other: &BitSet, mut f: F) where F: FnMut(u32, u32) -> u32 {
1366 let self_bit_vec = &mut self.bit_vec;
1367 let other_bit_vec = &other.bit_vec;
1369 let self_len = self_bit_vec.len();
1370 let other_len = other_bit_vec.len();
1372 // Expand the vector if necessary
1373 if self_len < other_len {
1374 self_bit_vec.grow(other_len - self_len, false);
1377 // virtually pad other with 0's for equal lengths
1379 let (_, result) = match_words(self_bit_vec, other_bit_vec);
1383 // Apply values found in other
1384 for (i, w) in other_words {
1385 let old = self_bit_vec.storage[i];
1386 let new = f(old, w);
1387 self_bit_vec.storage[i] = new;
1391 /// Truncates the underlying vector to the least length required.
1396 /// use std::collections::BitSet;
1398 /// let mut s = BitSet::new();
1399 /// s.insert(32183231);
1400 /// s.remove(&32183231);
1402 /// // Internal storage will probably be bigger than necessary
1403 /// println!("old capacity: {}", s.capacity());
1405 /// // Now should be smaller
1406 /// s.shrink_to_fit();
1407 /// println!("new capacity: {}", s.capacity());
1410 #[stable(feature = "rust1", since = "1.0.0")]
1411 pub fn shrink_to_fit(&mut self) {
1412 let bit_vec = &mut self.bit_vec;
1413 // Obtain original length
1414 let old_len = bit_vec.storage.len();
1415 // Obtain coarse trailing zero length
1416 let n = bit_vec.storage.iter().rev().take_while(|&&n| n == 0).count();
1418 let trunc_len = cmp::max(old_len - n, 1);
1419 bit_vec.storage.truncate(trunc_len);
1420 bit_vec.nbits = trunc_len * u32::BITS;
1423 /// Iterator over each u32 stored in the `BitSet`.
1428 /// use std::collections::{BitVec, BitSet};
1430 /// let s = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01001010]));
1432 /// // Print 1, 4, 6 in arbitrary order
1433 /// for x in s.iter() {
1434 /// println!("{}", x);
1438 #[stable(feature = "rust1", since = "1.0.0")]
1439 pub fn iter(&self) -> bit_set::Iter {
1440 SetIter {set: self, next_idx: 0}
1443 /// Iterator over each u32 stored in `self` union `other`.
1444 /// See [union_with](#method.union_with) for an efficient in-place version.
1449 /// use std::collections::{BitVec, BitSet};
1451 /// let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101000]));
1452 /// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100000]));
1454 /// // Print 0, 1, 2, 4 in arbitrary order
1455 /// for x in a.union(&b) {
1456 /// println!("{}", x);
1460 #[stable(feature = "rust1", since = "1.0.0")]
1461 pub fn union<'a>(&'a self, other: &'a BitSet) -> Union<'a> {
1462 fn or(w1: u32, w2: u32) -> u32 { w1 | w2 }
1464 Union(TwoBitPositions {
1473 /// Iterator over each usize stored in `self` intersect `other`.
1474 /// See [intersect_with](#method.intersect_with) for an efficient in-place version.
1479 /// use std::collections::{BitVec, BitSet};
1481 /// let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101000]));
1482 /// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100000]));
1485 /// for x in a.intersection(&b) {
1486 /// println!("{}", x);
1490 #[stable(feature = "rust1", since = "1.0.0")]
1491 pub fn intersection<'a>(&'a self, other: &'a BitSet) -> Intersection<'a> {
1492 fn bitand(w1: u32, w2: u32) -> u32 { w1 & w2 }
1493 let min = cmp::min(self.bit_vec.len(), other.bit_vec.len());
1494 Intersection(TwoBitPositions {
1503 /// Iterator over each usize stored in the `self` setminus `other`.
1504 /// See [difference_with](#method.difference_with) for an efficient in-place version.
1509 /// use std::collections::{BitSet, BitVec};
1511 /// let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101000]));
1512 /// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100000]));
1514 /// // Print 1, 4 in arbitrary order
1515 /// for x in a.difference(&b) {
1516 /// println!("{}", x);
1519 /// // Note that difference is not symmetric,
1520 /// // and `b - a` means something else.
1521 /// // This prints 0
1522 /// for x in b.difference(&a) {
1523 /// println!("{}", x);
1527 #[stable(feature = "rust1", since = "1.0.0")]
1528 pub fn difference<'a>(&'a self, other: &'a BitSet) -> Difference<'a> {
1529 fn diff(w1: u32, w2: u32) -> u32 { w1 & !w2 }
1531 Difference(TwoBitPositions {
1540 /// Iterator over each u32 stored in the symmetric difference of `self` and `other`.
1541 /// See [symmetric_difference_with](#method.symmetric_difference_with) for
1542 /// an efficient in-place version.
1547 /// use std::collections::{BitSet, BitVec};
1549 /// let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101000]));
1550 /// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100000]));
1552 /// // Print 0, 1, 4 in arbitrary order
1553 /// for x in a.symmetric_difference(&b) {
1554 /// println!("{}", x);
1558 #[stable(feature = "rust1", since = "1.0.0")]
1559 pub fn symmetric_difference<'a>(&'a self, other: &'a BitSet) -> SymmetricDifference<'a> {
1560 fn bitxor(w1: u32, w2: u32) -> u32 { w1 ^ w2 }
1562 SymmetricDifference(TwoBitPositions {
1571 /// Unions in-place with the specified other bit vector.
1576 /// use std::collections::{BitSet, BitVec};
1578 /// let a = 0b01101000;
1579 /// let b = 0b10100000;
1580 /// let res = 0b11101000;
1582 /// let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
1583 /// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
1584 /// let res = BitSet::from_bit_vec(BitVec::from_bytes(&[res]));
1586 /// a.union_with(&b);
1587 /// assert_eq!(a, res);
1590 pub fn union_with(&mut self, other: &BitSet) {
1591 self.other_op(other, |w1, w2| w1 | w2);
1594 /// Intersects in-place with the specified other bit vector.
1599 /// use std::collections::{BitSet, BitVec};
1601 /// let a = 0b01101000;
1602 /// let b = 0b10100000;
1603 /// let res = 0b00100000;
1605 /// let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
1606 /// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
1607 /// let res = BitSet::from_bit_vec(BitVec::from_bytes(&[res]));
1609 /// a.intersect_with(&b);
1610 /// assert_eq!(a, res);
1613 pub fn intersect_with(&mut self, other: &BitSet) {
1614 self.other_op(other, |w1, w2| w1 & w2);
1617 /// Makes this bit vector the difference with the specified other bit vector
1623 /// use std::collections::{BitSet, BitVec};
1625 /// let a = 0b01101000;
1626 /// let b = 0b10100000;
1627 /// let a_b = 0b01001000; // a - b
1628 /// let b_a = 0b10000000; // b - a
1630 /// let mut bva = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
1631 /// let bvb = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
1632 /// let bva_b = BitSet::from_bit_vec(BitVec::from_bytes(&[a_b]));
1633 /// let bvb_a = BitSet::from_bit_vec(BitVec::from_bytes(&[b_a]));
1635 /// bva.difference_with(&bvb);
1636 /// assert_eq!(bva, bva_b);
1638 /// let bva = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
1639 /// let mut bvb = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
1641 /// bvb.difference_with(&bva);
1642 /// assert_eq!(bvb, bvb_a);
1645 pub fn difference_with(&mut self, other: &BitSet) {
1646 self.other_op(other, |w1, w2| w1 & !w2);
1649 /// Makes this bit vector the symmetric difference with the specified other
1650 /// bit vector in-place.
1655 /// use std::collections::{BitSet, BitVec};
1657 /// let a = 0b01101000;
1658 /// let b = 0b10100000;
1659 /// let res = 0b11001000;
1661 /// let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[a]));
1662 /// let b = BitSet::from_bit_vec(BitVec::from_bytes(&[b]));
1663 /// let res = BitSet::from_bit_vec(BitVec::from_bytes(&[res]));
1665 /// a.symmetric_difference_with(&b);
1666 /// assert_eq!(a, res);
1669 pub fn symmetric_difference_with(&mut self, other: &BitSet) {
1670 self.other_op(other, |w1, w2| w1 ^ w2);
1673 /// Return the number of set bits in this set.
1675 #[stable(feature = "rust1", since = "1.0.0")]
1676 pub fn len(&self) -> usize {
1677 self.bit_vec.blocks().fold(0, |acc, n| acc + n.count_ones())
1680 /// Returns whether there are no bits set in this set
1682 #[stable(feature = "rust1", since = "1.0.0")]
1683 pub fn is_empty(&self) -> bool {
1687 /// Clears all bits in this set
1689 #[stable(feature = "rust1", since = "1.0.0")]
1690 pub fn clear(&mut self) {
1691 self.bit_vec.clear();
1694 /// Returns `true` if this set contains the specified integer.
1696 #[stable(feature = "rust1", since = "1.0.0")]
1697 pub fn contains(&self, value: &usize) -> bool {
1698 let bit_vec = &self.bit_vec;
1699 *value < bit_vec.nbits && bit_vec[*value]
1702 /// Returns `true` if the set has no elements in common with `other`.
1703 /// This is equivalent to checking for an empty intersection.
1705 #[stable(feature = "rust1", since = "1.0.0")]
1706 pub fn is_disjoint(&self, other: &BitSet) -> bool {
1707 self.intersection(other).next().is_none()
1710 /// Returns `true` if the set is a subset of another.
1712 #[stable(feature = "rust1", since = "1.0.0")]
1713 pub fn is_subset(&self, other: &BitSet) -> bool {
1714 let self_bit_vec = &self.bit_vec;
1715 let other_bit_vec = &other.bit_vec;
1716 let other_blocks = blocks_for_bits(other_bit_vec.len());
1718 // Check that `self` intersect `other` is self
1719 self_bit_vec.blocks().zip(other_bit_vec.blocks()).all(|(w1, w2)| w1 & w2 == w1) &&
1720 // Make sure if `self` has any more blocks than `other`, they're all 0
1721 self_bit_vec.blocks().skip(other_blocks).all(|w| w == 0)
1724 /// Returns `true` if the set is a superset of another.
1726 #[stable(feature = "rust1", since = "1.0.0")]
1727 pub fn is_superset(&self, other: &BitSet) -> bool {
1728 other.is_subset(self)
1731 /// Adds a value to the set. Returns `true` if the value was not already
1732 /// present in the set.
1733 #[stable(feature = "rust1", since = "1.0.0")]
1734 pub fn insert(&mut self, value: usize) -> bool {
1735 if self.contains(&value) {
1739 // Ensure we have enough space to hold the new element
1740 let len = self.bit_vec.len();
1742 self.bit_vec.grow(value - len + 1, false)
1745 self.bit_vec.set(value, true);
1749 /// Removes a value from the set. Returns `true` if the value was
1750 /// present in the set.
1751 #[stable(feature = "rust1", since = "1.0.0")]
1752 pub fn remove(&mut self, value: &usize) -> bool {
1753 if !self.contains(value) {
1757 self.bit_vec.set(*value, false);
1763 #[stable(feature = "rust1", since = "1.0.0")]
1764 impl fmt::Debug for BitSet {
1765 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
1766 try!(write!(fmt, "BitSet {{"));
1767 let mut first = true;
1770 try!(write!(fmt, ", "));
1772 try!(write!(fmt, "{:?}", n));
1780 impl<S: hash::Writer + hash::Hasher> hash::Hash<S> for BitSet {
1781 fn hash(&self, state: &mut S) {
1787 #[stable(feature = "rust1", since = "1.0.0")]
1789 impl hash::Hash for BitSet {
1790 fn hash<H: hash::Hasher>(&self, state: &mut H) {
1797 /// An iterator for `BitSet`.
1799 #[stable(feature = "rust1", since = "1.0.0")]
1800 pub struct SetIter<'a> {
1805 /// An iterator combining two `BitSet` iterators.
1807 struct TwoBitPositions<'a> {
1810 merge: fn(u32, u32) -> u32,
1815 #[stable(feature = "rust1", since = "1.0.0")]
1816 pub struct Union<'a>(TwoBitPositions<'a>);
1817 #[stable(feature = "rust1", since = "1.0.0")]
1818 pub struct Intersection<'a>(Take<TwoBitPositions<'a>>);
1819 #[stable(feature = "rust1", since = "1.0.0")]
1820 pub struct Difference<'a>(TwoBitPositions<'a>);
1821 #[stable(feature = "rust1", since = "1.0.0")]
1822 pub struct SymmetricDifference<'a>(TwoBitPositions<'a>);
1824 #[stable(feature = "rust1", since = "1.0.0")]
1825 impl<'a> Iterator for SetIter<'a> {
1828 fn next(&mut self) -> Option<usize> {
1829 while self.next_idx < self.set.bit_vec.len() {
1830 let idx = self.next_idx;
1833 if self.set.contains(&idx) {
1842 fn size_hint(&self) -> (usize, Option<usize>) {
1843 (0, Some(self.set.bit_vec.len() - self.next_idx))
1847 #[stable(feature = "rust1", since = "1.0.0")]
1848 impl<'a> Iterator for TwoBitPositions<'a> {
1851 fn next(&mut self) -> Option<usize> {
1852 while self.next_idx < self.set.bit_vec.len() ||
1853 self.next_idx < self.other.bit_vec.len() {
1854 let bit_idx = self.next_idx % u32::BITS;
1856 let s_bit_vec = &self.set.bit_vec;
1857 let o_bit_vec = &self.other.bit_vec;
1858 // Merging the two words is a bit of an awkward dance since
1859 // one BitVec might be longer than the other
1860 let word_idx = self.next_idx / u32::BITS;
1861 let w1 = if word_idx < s_bit_vec.storage.len() {
1862 s_bit_vec.storage[word_idx]
1864 let w2 = if word_idx < o_bit_vec.storage.len() {
1865 o_bit_vec.storage[word_idx]
1867 self.current_word = (self.merge)(w1, w2);
1871 if self.current_word & (1 << bit_idx) != 0 {
1872 return Some(self.next_idx - 1);
1879 fn size_hint(&self) -> (usize, Option<usize>) {
1880 let cap = cmp::max(self.set.bit_vec.len(), self.other.bit_vec.len());
1881 (0, Some(cap - self.next_idx))
1885 #[stable(feature = "rust1", since = "1.0.0")]
1886 impl<'a> Iterator for Union<'a> {
1889 #[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
1890 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
1893 #[stable(feature = "rust1", since = "1.0.0")]
1894 impl<'a> Iterator for Intersection<'a> {
1897 #[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
1898 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
1901 #[stable(feature = "rust1", since = "1.0.0")]
1902 impl<'a> Iterator for Difference<'a> {
1905 #[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
1906 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
1909 #[stable(feature = "rust1", since = "1.0.0")]
1910 impl<'a> Iterator for SymmetricDifference<'a> {
1913 #[inline] fn next(&mut self) -> Option<usize> { self.0.next() }
1914 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
1917 #[stable(feature = "rust1", since = "1.0.0")]
1918 impl<'a> IntoIterator for &'a BitSet {
1920 type IntoIter = SetIter<'a>;
1922 fn into_iter(self) -> SetIter<'a> {
1936 let zerolen = BitVec::new();
1937 assert_eq!(format!("{:?}", zerolen), "");
1939 let eightbits = BitVec::from_elem(8, false);
1940 assert_eq!(format!("{:?}", eightbits), "00000000")
1944 fn test_0_elements() {
1945 let act = BitVec::new();
1946 let exp = Vec::new();
1947 assert!(act.eq_vec(&exp));
1948 assert!(act.none() && act.all());
1952 fn test_1_element() {
1953 let mut act = BitVec::from_elem(1, false);
1954 assert!(act.eq_vec(&[false]));
1955 assert!(act.none() && !act.all());
1956 act = BitVec::from_elem(1, true);
1957 assert!(act.eq_vec(&[true]));
1958 assert!(!act.none() && act.all());
1962 fn test_2_elements() {
1963 let mut b = BitVec::from_elem(2, false);
1966 assert_eq!(format!("{:?}", b), "10");
1967 assert!(!b.none() && !b.all());
1971 fn test_10_elements() {
1975 act = BitVec::from_elem(10, false);
1976 assert!((act.eq_vec(
1977 &[false, false, false, false, false, false, false, false, false, false])));
1978 assert!(act.none() && !act.all());
1981 act = BitVec::from_elem(10, true);
1982 assert!((act.eq_vec(&[true, true, true, true, true, true, true, true, true, true])));
1983 assert!(!act.none() && act.all());
1986 act = BitVec::from_elem(10, false);
1992 assert!((act.eq_vec(&[true, true, true, true, true, false, false, false, false, false])));
1993 assert!(!act.none() && !act.all());
1996 act = BitVec::from_elem(10, false);
2002 assert!((act.eq_vec(&[false, false, false, false, false, true, true, true, true, true])));
2003 assert!(!act.none() && !act.all());
2006 act = BitVec::from_elem(10, false);
2011 assert!((act.eq_vec(&[true, false, false, true, false, false, true, false, false, true])));
2012 assert!(!act.none() && !act.all());
2016 fn test_31_elements() {
2020 act = BitVec::from_elem(31, false);
2022 &[false, false, false, false, false, false, false, false, false, false, false,
2023 false, false, false, false, false, false, false, false, false, false, false,
2024 false, false, false, false, false, false, false, false, false]));
2025 assert!(act.none() && !act.all());
2028 act = BitVec::from_elem(31, true);
2030 &[true, true, true, true, true, true, true, true, true, true, true, true, true,
2031 true, true, true, true, true, true, true, true, true, true, true, true, true,
2032 true, true, true, true, true]));
2033 assert!(!act.none() && act.all());
2036 act = BitVec::from_elem(31, false);
2046 &[true, true, true, true, true, true, true, true, false, false, false, false, false,
2047 false, false, false, false, false, false, false, false, false, false, false,
2048 false, false, false, false, false, false, false]));
2049 assert!(!act.none() && !act.all());
2052 act = BitVec::from_elem(31, false);
2062 &[false, false, false, false, false, false, false, false, false, false, false,
2063 false, false, false, false, false, true, true, true, true, true, true, true, true,
2064 false, false, false, false, false, false, false]));
2065 assert!(!act.none() && !act.all());
2068 act = BitVec::from_elem(31, false);
2077 &[false, false, false, false, false, false, false, false, false, false, false,
2078 false, false, false, false, false, false, false, false, false, false, false,
2079 false, false, true, true, true, true, true, true, true]));
2080 assert!(!act.none() && !act.all());
2083 act = BitVec::from_elem(31, false);
2088 &[false, false, false, true, false, false, false, false, false, false, false, false,
2089 false, false, false, false, false, true, false, false, false, false, false, false,
2090 false, false, false, false, false, false, true]));
2091 assert!(!act.none() && !act.all());
2095 fn test_32_elements() {
2099 act = BitVec::from_elem(32, false);
2101 &[false, false, false, false, false, false, false, false, false, false, false,
2102 false, false, false, false, false, false, false, false, false, false, false,
2103 false, false, false, false, false, false, false, false, false, false]));
2104 assert!(act.none() && !act.all());
2107 act = BitVec::from_elem(32, true);
2109 &[true, true, true, true, true, true, true, true, true, true, true, true, true,
2110 true, true, true, true, true, true, true, true, true, true, true, true, true,
2111 true, true, true, true, true, true]));
2112 assert!(!act.none() && act.all());
2115 act = BitVec::from_elem(32, false);
2125 &[true, true, true, true, true, true, true, true, false, false, false, false, false,
2126 false, false, false, false, false, false, false, false, false, false, false,
2127 false, false, false, false, false, false, false, false]));
2128 assert!(!act.none() && !act.all());
2131 act = BitVec::from_elem(32, false);
2141 &[false, false, false, false, false, false, false, false, false, false, false,
2142 false, false, false, false, false, true, true, true, true, true, true, true, true,
2143 false, false, false, false, false, false, false, false]));
2144 assert!(!act.none() && !act.all());
2147 act = BitVec::from_elem(32, false);
2157 &[false, false, false, false, false, false, false, false, false, false, false,
2158 false, false, false, false, false, false, false, false, false, false, false,
2159 false, false, true, true, true, true, true, true, true, true]));
2160 assert!(!act.none() && !act.all());
2163 act = BitVec::from_elem(32, false);
2169 &[false, false, false, true, false, false, false, false, false, false, false, false,
2170 false, false, false, false, false, true, false, false, false, false, false, false,
2171 false, false, false, false, false, false, true, true]));
2172 assert!(!act.none() && !act.all());
2176 fn test_33_elements() {
2180 act = BitVec::from_elem(33, false);
2182 &[false, false, false, false, false, false, false, false, false, false, false,
2183 false, false, false, false, false, false, false, false, false, false, false,
2184 false, false, false, false, false, false, false, false, false, false, false]));
2185 assert!(act.none() && !act.all());
2188 act = BitVec::from_elem(33, true);
2190 &[true, true, true, true, true, true, true, true, true, true, true, true, true,
2191 true, true, true, true, true, true, true, true, true, true, true, true, true,
2192 true, true, true, true, true, true, true]));
2193 assert!(!act.none() && act.all());
2196 act = BitVec::from_elem(33, false);
2206 &[true, true, true, true, true, true, true, true, false, false, false, false, false,
2207 false, false, false, false, false, false, false, false, false, false, false,
2208 false, false, false, false, false, false, false, false, false]));
2209 assert!(!act.none() && !act.all());
2212 act = BitVec::from_elem(33, false);
2222 &[false, false, false, false, false, false, false, false, false, false, false,
2223 false, false, false, false, false, true, true, true, true, true, true, true, true,
2224 false, false, false, false, false, false, false, false, false]));
2225 assert!(!act.none() && !act.all());
2228 act = BitVec::from_elem(33, false);
2238 &[false, false, false, false, false, false, false, false, false, false, false,
2239 false, false, false, false, false, false, false, false, false, false, false,
2240 false, false, true, true, true, true, true, true, true, true, false]));
2241 assert!(!act.none() && !act.all());
2244 act = BitVec::from_elem(33, false);
2251 &[false, false, false, true, false, false, false, false, false, false, false, false,
2252 false, false, false, false, false, true, false, false, false, false, false, false,
2253 false, false, false, false, false, false, true, true, true]));
2254 assert!(!act.none() && !act.all());
2258 fn test_equal_differing_sizes() {
2259 let v0 = BitVec::from_elem(10, false);
2260 let v1 = BitVec::from_elem(11, false);
2265 fn test_equal_greatly_differing_sizes() {
2266 let v0 = BitVec::from_elem(10, false);
2267 let v1 = BitVec::from_elem(110, false);
2272 fn test_equal_sneaky_small() {
2273 let mut a = BitVec::from_elem(1, false);
2276 let mut b = BitVec::from_elem(1, true);
2283 fn test_equal_sneaky_big() {
2284 let mut a = BitVec::from_elem(100, false);
2289 let mut b = BitVec::from_elem(100, true);
2298 fn test_from_bytes() {
2299 let bit_vec = BitVec::from_bytes(&[0b10110110, 0b00000000, 0b11111111]);
2300 let str = concat!("10110110", "00000000", "11111111");
2301 assert_eq!(format!("{:?}", bit_vec), str);
2305 fn test_to_bytes() {
2306 let mut bv = BitVec::from_elem(3, true);
2308 assert_eq!(bv.to_bytes(), vec!(0b10100000));
2310 let mut bv = BitVec::from_elem(9, false);
2313 assert_eq!(bv.to_bytes(), vec!(0b00100000, 0b10000000));
2317 fn test_from_bools() {
2318 let bools = vec![true, false, true, true];
2319 let bit_vec: BitVec = bools.iter().map(|n| *n).collect();
2320 assert_eq!(format!("{:?}", bit_vec), "1011");
2324 fn test_to_bools() {
2325 let bools = vec![false, false, true, false, false, true, true, false];
2326 assert_eq!(BitVec::from_bytes(&[0b00100110]).iter().collect::<Vec<bool>>(), bools);
2330 fn test_bit_vec_iterator() {
2331 let bools = vec![true, false, true, true];
2332 let bit_vec: BitVec = bools.iter().map(|n| *n).collect();
2334 assert_eq!(bit_vec.iter().collect::<Vec<bool>>(), bools);
2336 let long: Vec<_> = (0i32..10000).map(|i| i % 2 == 0).collect();
2337 let bit_vec: BitVec = long.iter().map(|n| *n).collect();
2338 assert_eq!(bit_vec.iter().collect::<Vec<bool>>(), long)
2342 fn test_small_difference() {
2343 let mut b1 = BitVec::from_elem(3, false);
2344 let mut b2 = BitVec::from_elem(3, false);
2349 assert!(b1.difference(&b2));
2356 fn test_big_difference() {
2357 let mut b1 = BitVec::from_elem(100, false);
2358 let mut b2 = BitVec::from_elem(100, false);
2363 assert!(b1.difference(&b2));
2370 fn test_small_clear() {
2371 let mut b = BitVec::from_elem(14, true);
2372 assert!(!b.none() && b.all());
2374 assert!(b.none() && !b.all());
2378 fn test_big_clear() {
2379 let mut b = BitVec::from_elem(140, true);
2380 assert!(!b.none() && b.all());
2382 assert!(b.none() && !b.all());
2386 fn test_bit_vec_lt() {
2387 let mut a = BitVec::from_elem(5, false);
2388 let mut b = BitVec::from_elem(5, false);
2390 assert!(!(a < b) && !(b < a));
2396 assert!(!(a < b) && b < a);
2403 let mut a = BitVec::from_elem(5, false);
2404 let mut b = BitVec::from_elem(5, false);
2406 assert!(a <= b && a >= b);
2408 assert!(a > b && a >= b);
2409 assert!(b < a && b <= a);
2412 assert!(b > a && b >= a);
2413 assert!(a < b && a <= b);
2418 fn test_small_bit_vec_tests() {
2419 let v = BitVec::from_bytes(&[0]);
2424 let v = BitVec::from_bytes(&[0b00010100]);
2429 let v = BitVec::from_bytes(&[0xFF]);
2436 fn test_big_bit_vec_tests() {
2437 let v = BitVec::from_bytes(&[ // 88 bits
2445 let v = BitVec::from_bytes(&[ // 88 bits
2446 0, 0, 0b00010100, 0,
2447 0, 0, 0, 0b00110100,
2453 let v = BitVec::from_bytes(&[ // 88 bits
2454 0xFF, 0xFF, 0xFF, 0xFF,
2455 0xFF, 0xFF, 0xFF, 0xFF,
2463 fn test_bit_vec_push_pop() {
2464 let mut s = BitVec::from_elem(5 * u32::BITS - 2, false);
2465 assert_eq!(s.len(), 5 * u32::BITS - 2);
2466 assert_eq!(s[5 * u32::BITS - 3], false);
2469 assert_eq!(s[5 * u32::BITS - 2], true);
2470 assert_eq!(s[5 * u32::BITS - 1], true);
2471 // Here the internal vector will need to be extended
2473 assert_eq!(s[5 * u32::BITS], false);
2475 assert_eq!(s[5 * u32::BITS + 1], false);
2476 assert_eq!(s.len(), 5 * u32::BITS + 2);
2478 assert_eq!(s.pop(), Some(false));
2479 assert_eq!(s.pop(), Some(false));
2480 assert_eq!(s.pop(), Some(true));
2481 assert_eq!(s.pop(), Some(true));
2482 assert_eq!(s.len(), 5 * u32::BITS - 2);
2486 fn test_bit_vec_truncate() {
2487 let mut s = BitVec::from_elem(5 * u32::BITS, true);
2489 assert_eq!(s, BitVec::from_elem(5 * u32::BITS, true));
2490 assert_eq!(s.len(), 5 * u32::BITS);
2491 s.truncate(4 * u32::BITS);
2492 assert_eq!(s, BitVec::from_elem(4 * u32::BITS, true));
2493 assert_eq!(s.len(), 4 * u32::BITS);
2494 // Truncating to a size > s.len() should be a noop
2495 s.truncate(5 * u32::BITS);
2496 assert_eq!(s, BitVec::from_elem(4 * u32::BITS, true));
2497 assert_eq!(s.len(), 4 * u32::BITS);
2498 s.truncate(3 * u32::BITS - 10);
2499 assert_eq!(s, BitVec::from_elem(3 * u32::BITS - 10, true));
2500 assert_eq!(s.len(), 3 * u32::BITS - 10);
2502 assert_eq!(s, BitVec::from_elem(0, true));
2503 assert_eq!(s.len(), 0);
2507 fn test_bit_vec_reserve() {
2508 let mut s = BitVec::from_elem(5 * u32::BITS, true);
2510 assert!(s.capacity() >= 5 * u32::BITS);
2511 s.reserve(2 * u32::BITS);
2512 assert!(s.capacity() >= 7 * u32::BITS);
2513 s.reserve(7 * u32::BITS);
2514 assert!(s.capacity() >= 12 * u32::BITS);
2515 s.reserve_exact(7 * u32::BITS);
2516 assert!(s.capacity() >= 12 * u32::BITS);
2517 s.reserve(7 * u32::BITS + 1);
2518 assert!(s.capacity() >= 12 * u32::BITS + 1);
2519 // Check that length hasn't changed
2520 assert_eq!(s.len(), 5 * u32::BITS);
2524 assert_eq!(s[5 * u32::BITS - 1], true);
2525 assert_eq!(s[5 * u32::BITS - 0], true);
2526 assert_eq!(s[5 * u32::BITS + 1], false);
2527 assert_eq!(s[5 * u32::BITS + 2], true);
2531 fn test_bit_vec_grow() {
2532 let mut bit_vec = BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010]);
2533 bit_vec.grow(32, true);
2534 assert_eq!(bit_vec, BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010,
2535 0xFF, 0xFF, 0xFF, 0xFF]));
2536 bit_vec.grow(64, false);
2537 assert_eq!(bit_vec, BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010,
2538 0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0]));
2539 bit_vec.grow(16, true);
2540 assert_eq!(bit_vec, BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010,
2541 0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF]));
2545 fn test_bit_vec_extend() {
2546 let mut bit_vec = BitVec::from_bytes(&[0b10110110, 0b00000000, 0b11111111]);
2547 let ext = BitVec::from_bytes(&[0b01001001, 0b10010010, 0b10111101]);
2548 bit_vec.extend(ext.iter());
2549 assert_eq!(bit_vec, BitVec::from_bytes(&[0b10110110, 0b00000000, 0b11111111,
2550 0b01001001, 0b10010010, 0b10111101]));
2559 use std::prelude::v1::*;
2563 use test::{Bencher, black_box};
2567 static BENCH_BITS : usize = 1 << 14;
2569 fn rng() -> rand::IsaacRng {
2570 let seed: &[_] = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
2571 rand::SeedableRng::from_seed(seed)
2575 fn bench_usize_small(b: &mut Bencher) {
2577 let mut bit_vec = 0 as usize;
2580 bit_vec |= 1 << ((r.next_u32() as usize) % u32::BITS);
2582 black_box(&bit_vec);
2587 fn bench_bit_set_big_fixed(b: &mut Bencher) {
2589 let mut bit_vec = BitVec::from_elem(BENCH_BITS, false);
2592 bit_vec.set((r.next_u32() as usize) % BENCH_BITS, true);
2594 black_box(&bit_vec);
2599 fn bench_bit_set_big_variable(b: &mut Bencher) {
2601 let mut bit_vec = BitVec::from_elem(BENCH_BITS, false);
2604 bit_vec.set((r.next_u32() as usize) % BENCH_BITS, r.gen());
2606 black_box(&bit_vec);
2611 fn bench_bit_set_small(b: &mut Bencher) {
2613 let mut bit_vec = BitVec::from_elem(u32::BITS, false);
2616 bit_vec.set((r.next_u32() as usize) % u32::BITS, true);
2618 black_box(&bit_vec);
2623 fn bench_bit_vec_big_union(b: &mut Bencher) {
2624 let mut b1 = BitVec::from_elem(BENCH_BITS, false);
2625 let b2 = BitVec::from_elem(BENCH_BITS, false);
2632 fn bench_bit_vec_small_iter(b: &mut Bencher) {
2633 let bit_vec = BitVec::from_elem(u32::BITS, false);
2637 for pres in &bit_vec {
2638 sum += pres as usize;
2646 fn bench_bit_vec_big_iter(b: &mut Bencher) {
2647 let bit_vec = BitVec::from_elem(BENCH_BITS, false);
2650 for pres in &bit_vec {
2651 sum += pres as usize;
2667 use std::iter::range_step;
2669 use super::{BitVec, BitSet};
2672 fn test_bit_set_show() {
2673 let mut s = BitSet::new();
2678 assert_eq!("BitSet {1, 2, 10, 50}", format!("{:?}", s));
2682 fn test_bit_set_from_usizes() {
2683 let usizes = vec![0, 2, 2, 3];
2684 let a: BitSet = usizes.into_iter().collect();
2685 let mut b = BitSet::new();
2693 fn test_bit_set_iterator() {
2694 let usizes = vec![0, 2, 2, 3];
2695 let bit_vec: BitSet = usizes.into_iter().collect();
2697 let idxs: Vec<_> = bit_vec.iter().collect();
2698 assert_eq!(idxs, vec![0, 2, 3]);
2700 let long: BitSet = (0..10000).filter(|&n| n % 2 == 0).collect();
2701 let real: Vec<_> = range_step(0, 10000, 2).collect();
2703 let idxs: Vec<_> = long.iter().collect();
2704 assert_eq!(idxs, real);
2708 fn test_bit_set_frombit_vec_init() {
2709 let bools = [true, false];
2710 let lengths = [10, 64, 100];
2712 for &l in &lengths {
2713 let bitset = BitSet::from_bit_vec(BitVec::from_elem(l, b));
2714 assert_eq!(bitset.contains(&1), b);
2715 assert_eq!(bitset.contains(&(l-1)), b);
2716 assert!(!bitset.contains(&l));
2722 fn test_bit_vec_masking() {
2723 let b = BitVec::from_elem(140, true);
2724 let mut bs = BitSet::from_bit_vec(b);
2725 assert!(bs.contains(&139));
2726 assert!(!bs.contains(&140));
2727 assert!(bs.insert(150));
2728 assert!(!bs.contains(&140));
2729 assert!(!bs.contains(&149));
2730 assert!(bs.contains(&150));
2731 assert!(!bs.contains(&151));
2735 fn test_bit_set_basic() {
2736 let mut b = BitSet::new();
2737 assert!(b.insert(3));
2738 assert!(!b.insert(3));
2739 assert!(b.contains(&3));
2740 assert!(b.insert(4));
2741 assert!(!b.insert(4));
2742 assert!(b.contains(&3));
2743 assert!(b.insert(400));
2744 assert!(!b.insert(400));
2745 assert!(b.contains(&400));
2746 assert_eq!(b.len(), 3);
2750 fn test_bit_set_intersection() {
2751 let mut a = BitSet::new();
2752 let mut b = BitSet::new();
2754 assert!(a.insert(11));
2755 assert!(a.insert(1));
2756 assert!(a.insert(3));
2757 assert!(a.insert(77));
2758 assert!(a.insert(103));
2759 assert!(a.insert(5));
2761 assert!(b.insert(2));
2762 assert!(b.insert(11));
2763 assert!(b.insert(77));
2764 assert!(b.insert(5));
2765 assert!(b.insert(3));
2767 let expected = [3, 5, 11, 77];
2768 let actual: Vec<_> = a.intersection(&b).collect();
2769 assert_eq!(actual, expected);
2773 fn test_bit_set_difference() {
2774 let mut a = BitSet::new();
2775 let mut b = BitSet::new();
2777 assert!(a.insert(1));
2778 assert!(a.insert(3));
2779 assert!(a.insert(5));
2780 assert!(a.insert(200));
2781 assert!(a.insert(500));
2783 assert!(b.insert(3));
2784 assert!(b.insert(200));
2786 let expected = [1, 5, 500];
2787 let actual: Vec<_> = a.difference(&b).collect();
2788 assert_eq!(actual, expected);
2792 fn test_bit_set_symmetric_difference() {
2793 let mut a = BitSet::new();
2794 let mut b = BitSet::new();
2796 assert!(a.insert(1));
2797 assert!(a.insert(3));
2798 assert!(a.insert(5));
2799 assert!(a.insert(9));
2800 assert!(a.insert(11));
2802 assert!(b.insert(3));
2803 assert!(b.insert(9));
2804 assert!(b.insert(14));
2805 assert!(b.insert(220));
2807 let expected = [1, 5, 11, 14, 220];
2808 let actual: Vec<_> = a.symmetric_difference(&b).collect();
2809 assert_eq!(actual, expected);
2813 fn test_bit_set_union() {
2814 let mut a = BitSet::new();
2815 let mut b = BitSet::new();
2816 assert!(a.insert(1));
2817 assert!(a.insert(3));
2818 assert!(a.insert(5));
2819 assert!(a.insert(9));
2820 assert!(a.insert(11));
2821 assert!(a.insert(160));
2822 assert!(a.insert(19));
2823 assert!(a.insert(24));
2824 assert!(a.insert(200));
2826 assert!(b.insert(1));
2827 assert!(b.insert(5));
2828 assert!(b.insert(9));
2829 assert!(b.insert(13));
2830 assert!(b.insert(19));
2832 let expected = [1, 3, 5, 9, 11, 13, 19, 24, 160, 200];
2833 let actual: Vec<_> = a.union(&b).collect();
2834 assert_eq!(actual, expected);
2838 fn test_bit_set_subset() {
2839 let mut set1 = BitSet::new();
2840 let mut set2 = BitSet::new();
2842 assert!(set1.is_subset(&set2)); // {} {}
2844 assert!(set1.is_subset(&set2)); // {} { 1 }
2846 assert!(set1.is_subset(&set2)); // {} { 1, 2 }
2848 assert!(set1.is_subset(&set2)); // { 2 } { 1, 2 }
2850 assert!(!set1.is_subset(&set2)); // { 2, 3 } { 1, 2 }
2852 assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3 }
2854 assert!(set1.is_subset(&set2)); // { 2, 3 } { 1, 2, 3, 4 }
2856 assert!(set1.is_subset(&set2)); // { 2, 3 } { 2, 3, 4 }
2858 assert!(!set1.is_subset(&set2)); // { 2, 3 } { 2, 4 }
2860 assert!(set1.is_subset(&set2)); // { 2 } { 2, 4 }
2864 fn test_bit_set_is_disjoint() {
2865 let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
2866 let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01000000]));
2867 let c = BitSet::new();
2868 let d = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00110000]));
2870 assert!(!a.is_disjoint(&d));
2871 assert!(!d.is_disjoint(&a));
2873 assert!(a.is_disjoint(&b));
2874 assert!(a.is_disjoint(&c));
2875 assert!(b.is_disjoint(&a));
2876 assert!(b.is_disjoint(&c));
2877 assert!(c.is_disjoint(&a));
2878 assert!(c.is_disjoint(&b));
2882 fn test_bit_set_union_with() {
2883 //a should grow to include larger elements
2884 let mut a = BitSet::new();
2886 let mut b = BitSet::new();
2888 let expected = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10000100]));
2890 assert_eq!(a, expected);
2893 let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
2894 let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01100010]));
2898 assert_eq!(a.len(), 4);
2899 assert_eq!(b.len(), 4);
2903 fn test_bit_set_intersect_with() {
2904 // Explicitly 0'ed bits
2905 let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
2906 let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00000000]));
2908 a.intersect_with(&b);
2909 b.intersect_with(&c);
2910 assert!(a.is_empty());
2911 assert!(b.is_empty());
2913 // Uninitialized bits should behave like 0's
2914 let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
2915 let mut b = BitSet::new();
2917 a.intersect_with(&b);
2918 b.intersect_with(&c);
2919 assert!(a.is_empty());
2920 assert!(b.is_empty());
2923 let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
2924 let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01100010]));
2926 a.intersect_with(&b);
2927 b.intersect_with(&c);
2928 assert_eq!(a.len(), 2);
2929 assert_eq!(b.len(), 2);
2933 fn test_bit_set_difference_with() {
2934 // Explicitly 0'ed bits
2935 let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00000000]));
2936 let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
2937 a.difference_with(&b);
2938 assert!(a.is_empty());
2940 // Uninitialized bits should behave like 0's
2941 let mut a = BitSet::new();
2942 let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b11111111]));
2943 a.difference_with(&b);
2944 assert!(a.is_empty());
2947 let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
2948 let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01100010]));
2950 a.difference_with(&b);
2951 b.difference_with(&c);
2952 assert_eq!(a.len(), 1);
2953 assert_eq!(b.len(), 1);
2957 fn test_bit_set_symmetric_difference_with() {
2958 //a should grow to include larger elements
2959 let mut a = BitSet::new();
2962 let mut b = BitSet::new();
2965 let expected = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10000100]));
2966 a.symmetric_difference_with(&b);
2967 assert_eq!(a, expected);
2969 let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
2970 let b = BitSet::new();
2972 a.symmetric_difference_with(&b);
2976 let mut a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b11100010]));
2977 let mut b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b01101010]));
2979 a.symmetric_difference_with(&b);
2980 b.symmetric_difference_with(&c);
2981 assert_eq!(a.len(), 2);
2982 assert_eq!(b.len(), 2);
2986 fn test_bit_set_eq() {
2987 let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
2988 let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00000000]));
2989 let c = BitSet::new();
3000 fn test_bit_set_cmp() {
3001 let a = BitSet::from_bit_vec(BitVec::from_bytes(&[0b10100010]));
3002 let b = BitSet::from_bit_vec(BitVec::from_bytes(&[0b00000000]));
3003 let c = BitSet::new();
3005 assert_eq!(a.cmp(&b), Greater);
3006 assert_eq!(a.cmp(&c), Greater);
3007 assert_eq!(b.cmp(&a), Less);
3008 assert_eq!(b.cmp(&c), Equal);
3009 assert_eq!(c.cmp(&a), Less);
3010 assert_eq!(c.cmp(&b), Equal);
3014 fn test_bit_vec_remove() {
3015 let mut a = BitSet::new();
3017 assert!(a.insert(1));
3018 assert!(a.remove(&1));
3020 assert!(a.insert(100));
3021 assert!(a.remove(&100));
3023 assert!(a.insert(1000));
3024 assert!(a.remove(&1000));
3029 fn test_bit_vec_clone() {
3030 let mut a = BitSet::new();
3032 assert!(a.insert(1));
3033 assert!(a.insert(100));
3034 assert!(a.insert(1000));
3036 let mut b = a.clone();
3040 assert!(b.remove(&1));
3041 assert!(a.contains(&1));
3043 assert!(a.remove(&1000));
3044 assert!(b.contains(&1000));
3054 use std::prelude::v1::*;
3058 use test::{Bencher, black_box};
3060 use super::{BitVec, BitSet};
3062 static BENCH_BITS : usize = 1 << 14;
3064 fn rng() -> rand::IsaacRng {
3065 let seed: &[_] = &[1, 2, 3, 4, 5, 6, 7, 8, 9, 0];
3066 rand::SeedableRng::from_seed(seed)
3070 fn bench_bit_vecset_small(b: &mut Bencher) {
3072 let mut bit_vec = BitSet::new();
3075 bit_vec.insert((r.next_u32() as usize) % u32::BITS);
3077 black_box(&bit_vec);
3082 fn bench_bit_vecset_big(b: &mut Bencher) {
3084 let mut bit_vec = BitSet::new();
3087 bit_vec.insert((r.next_u32() as usize) % BENCH_BITS);
3089 black_box(&bit_vec);
3094 fn bench_bit_vecset_iter(b: &mut Bencher) {
3095 let bit_vec = BitSet::from_bit_vec(BitVec::from_fn(BENCH_BITS,
3096 |idx| {idx % 3 == 0}));
3099 for idx in &bit_vec {
3100 sum += idx as usize;