Source code
Revision control
Copy as Markdown
Other Tools
// Copyright 2012-2023 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// FIXME(Gankro): BitVec and BitSet are very tightly coupled. Ideally (for
// maintenance), they should be in separate files/modules, with BitSet only
// using BitVec's public API. This will be hard for performance though, because
// `BitVec` will not want to leak its internal representation while its internal
// representation as `u32`s must be assumed for best performance.
// (1) Be careful, most things can overflow here because the amount of bits in
// memory can overflow `usize`.
// (2) Make sure that the underlying vector has no excess length:
// E. g. `nbits == 16`, `storage.len() == 2` would be excess length,
// because the last word isn't used at all. This is important because some
// methods rely on it (for *CORRECTNESS*).
// (3) Make sure that the unused bits in the last word are zeroed out, again
// other methods rely on it for *CORRECTNESS*.
// (4) `BitSet` is tightly coupled with `BitVec`, so any changes you make in
// `BitVec` will need to be reflected in `BitSet`.
//! # Description
//!
//! Dynamic collections implemented with compact bit vectors.
//!
//! # Examples
//!
//! This is a simple example of the [Sieve of Eratosthenes][sieve]
//! which calculates prime numbers up to a given limit.
//!
//!
//! ```
//! use bit_vec::BitVec;
//!
//! let max_prime = 10000;
//!
//! // Store the primes as a BitVec
//! let primes = {
//! // Assume all numbers are prime to begin, and then we
//! // cross off non-primes progressively
//! let mut bv = BitVec::from_elem(max_prime, true);
//!
//! // Neither 0 nor 1 are prime
//! bv.set(0, false);
//! bv.set(1, false);
//!
//! for i in 2.. 1 + (max_prime as f64).sqrt() as usize {
//! // if i is a prime
//! if bv[i] {
//! // Mark all multiples of i as non-prime (any multiples below i * i
//! // will have been marked as non-prime previously)
//! for j in i.. {
//! if i * j >= max_prime {
//! break;
//! }
//! bv.set(i * j, false)
//! }
//! }
//! }
//! bv
//! };
//!
//! // Simple primality tests below our max bound
//! let print_primes = 20;
//! print!("The primes below {} are: ", print_primes);
//! for x in 0..print_primes {
//! if primes.get(x).unwrap_or(false) {
//! print!("{} ", x);
//! }
//! }
//! println!();
//!
//! let num_primes = primes.iter().filter(|x| *x).count();
//! println!("There are {} primes below {}", num_primes, max_prime);
//! assert_eq!(num_primes, 1_229);
//! ```
#![no_std]
#[cfg(any(test, feature = "std"))]
#[macro_use]
extern crate std;
#[cfg(feature = "std")]
use std::rc::Rc;
#[cfg(feature = "std")]
use std::string::String;
#[cfg(feature = "std")]
use std::vec::Vec;
#[cfg(feature = "serde")]
extern crate serde;
#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};
#[cfg(feature = "borsh")]
extern crate borsh;
#[cfg(feature = "miniserde")]
extern crate miniserde;
#[cfg(feature = "nanoserde")]
extern crate nanoserde;
#[cfg(feature = "nanoserde")]
use nanoserde::{DeBin, DeJson, DeRon, SerBin, SerJson, SerRon};
#[cfg(not(feature = "std"))]
#[macro_use]
extern crate alloc;
#[cfg(not(feature = "std"))]
use alloc::rc::Rc;
#[cfg(not(feature = "std"))]
use alloc::string::String;
#[cfg(not(feature = "std"))]
use alloc::vec::Vec;
use core::cell::RefCell;
use core::cmp;
use core::cmp::Ordering;
use core::fmt::{self, Write};
use core::hash;
use core::iter::repeat;
use core::iter::FromIterator;
use core::mem;
use core::ops::*;
use core::slice;
type MutBlocks<'a, B> = slice::IterMut<'a, B>;
/// Abstracts over a pile of bits (basically unsigned primitives)
pub trait BitBlock:
Copy
+ Add<Self, Output = Self>
+ Sub<Self, Output = Self>
+ Shl<usize, Output = Self>
+ Shr<usize, Output = Self>
+ Not<Output = Self>
+ BitAnd<Self, Output = Self>
+ BitOr<Self, Output = Self>
+ BitXor<Self, Output = Self>
+ Rem<Self, Output = Self>
+ Eq
+ Ord
+ hash::Hash
{
/// How many bits it has
fn bits() -> usize;
/// How many bytes it has
#[inline]
fn bytes() -> usize {
Self::bits() / 8
}
/// Convert a byte into this type (lowest-order bits set)
fn from_byte(byte: u8) -> Self;
/// Count the number of 1's in the bitwise repr
fn count_ones(self) -> usize;
/// Count the number of 0's in the bitwise repr
fn count_zeros(self) -> usize {
Self::bits() - self.count_ones()
}
/// Get `0`
fn zero() -> Self;
/// Get `1`
fn one() -> Self;
}
macro_rules! bit_block_impl {
($(($t: ident, $size: expr)),*) => ($(
impl BitBlock for $t {
#[inline]
fn bits() -> usize { $size }
#[inline]
fn from_byte(byte: u8) -> Self { $t::from(byte) }
#[inline]
fn count_ones(self) -> usize { self.count_ones() as usize }
#[inline]
fn count_zeros(self) -> usize { self.count_zeros() as usize }
#[inline]
fn one() -> Self { 1 }
#[inline]
fn zero() -> Self { 0 }
}
)*)
}
bit_block_impl! {
(u8, 8),
(u16, 16),
(u32, 32),
(u64, 64),
(usize, core::mem::size_of::<usize>() * 8)
}
fn reverse_bits(byte: u8) -> u8 {
let mut result = 0;
for i in 0..u8::bits() {
result |= ((byte >> i) & 1) << (u8::bits() - 1 - i);
}
result
}
static TRUE: bool = true;
static FALSE: bool = false;
/// The bitvector type.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(10, false);
///
/// // insert all primes less than 10
/// bv.set(2, true);
/// bv.set(3, true);
/// bv.set(5, true);
/// bv.set(7, true);
/// println!("{:?}", bv);
/// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
///
/// // flip all values in bitvector, producing non-primes less than 10
/// bv.negate();
/// println!("{:?}", bv);
/// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
///
/// // reset bitvector to empty
/// bv.clear();
/// println!("{:?}", bv);
/// println!("total bits set to true: {}", bv.iter().filter(|x| *x).count());
/// ```
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(
feature = "borsh",
derive(borsh::BorshDeserialize, borsh::BorshSerialize)
)]
#[cfg_attr(
feature = "miniserde",
derive(miniserde::Deserialize, miniserde::Serialize)
)]
#[cfg_attr(
feature = "nanoserde",
derive(DeBin, DeJson, DeRon, SerBin, SerJson, SerRon)
)]
pub struct BitVec<B = u32> {
/// Internal representation of the bit vector
storage: Vec<B>,
/// The number of valid bits in the internal representation
nbits: usize,
}
// FIXME(Gankro): NopeNopeNopeNopeNope (wait for IndexGet to be a thing)
impl<B: BitBlock> Index<usize> for BitVec<B> {
type Output = bool;
#[inline]
fn index(&self, i: usize) -> &bool {
if self.get(i).expect("index out of bounds") {
&TRUE
} else {
&FALSE
}
}
}
/// 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 + U32_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
}
}
/// Computes the bitmask for the final word of the vector
fn mask_for_bits<B: BitBlock>(bits: usize) -> B {
// Note especially that a perfect multiple of U32_BITS should mask all 1s.
(!B::zero()) >> ((B::bits() - bits % B::bits()) % B::bits())
}
type B = u32;
impl BitVec<u32> {
/// Creates an empty `BitVec`.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
/// let mut bv = BitVec::new();
/// ```
#[inline]
pub fn new() -> Self {
Default::default()
}
/// Creates a `BitVec` that holds `nbits` elements, setting each element
/// to `bit`.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(10, false);
/// assert_eq!(bv.len(), 10);
/// for x in bv.iter() {
/// assert_eq!(x, false);
/// }
/// ```
#[inline]
pub fn from_elem(nbits: usize, bit: bool) -> Self {
let nblocks = blocks_for_bits::<B>(nbits);
let mut bit_vec = BitVec {
storage: vec![if bit { !B::zero() } else { B::zero() }; nblocks],
nbits,
};
bit_vec.fix_last_block();
bit_vec
}
/// Constructs a new, empty `BitVec` with the specified capacity.
///
/// The bitvector will be able to hold at least `capacity` bits without
/// reallocating. If `capacity` is 0, it will not allocate.
///
/// It is important to note that this function does not specify the
/// *length* of the returned bitvector, but only the *capacity*.
#[inline]
pub fn with_capacity(nbits: usize) -> Self {
BitVec {
storage: Vec::with_capacity(blocks_for_bits::<B>(nbits)),
nbits: 0,
}
}
/// Transforms a byte-vector into a `BitVec`. Each byte becomes eight bits,
/// with the most significant bits of each byte coming first. Each
/// bit becomes `true` if equal to 1 or `false` if equal to 0.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let bv = BitVec::from_bytes(&[0b10100000, 0b00010010]);
/// assert!(bv.eq_vec(&[true, false, true, false,
/// false, false, false, false,
/// false, false, false, true,
/// false, false, true, false]));
/// ```
pub fn from_bytes(bytes: &[u8]) -> Self {
let len = bytes
.len()
.checked_mul(u8::bits())
.expect("capacity overflow");
let mut bit_vec = BitVec::with_capacity(len);
let complete_words = bytes.len() / B::bytes();
let extra_bytes = bytes.len() % B::bytes();
bit_vec.nbits = len;
for i in 0..complete_words {
let mut accumulator = B::zero();
for idx in 0..B::bytes() {
accumulator |= B::from_byte(reverse_bits(bytes[i * B::bytes() + idx])) << (idx * 8)
}
bit_vec.storage.push(accumulator);
}
if extra_bytes > 0 {
let mut last_word = B::zero();
for (i, &byte) in bytes[complete_words * B::bytes()..].iter().enumerate() {
last_word |= B::from_byte(reverse_bits(byte)) << (i * 8);
}
bit_vec.storage.push(last_word);
}
bit_vec
}
/// Creates a `BitVec` of the specified length where the value at each index
/// is `f(index)`.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let bv = BitVec::from_fn(5, |i| { i % 2 == 0 });
/// assert!(bv.eq_vec(&[true, false, true, false, true]));
/// ```
#[inline]
pub fn from_fn<F>(len: usize, mut f: F) -> Self
where
F: FnMut(usize) -> bool,
{
let mut bit_vec = BitVec::from_elem(len, false);
for i in 0..len {
bit_vec.set(i, f(i));
}
bit_vec
}
}
impl<B: BitBlock> BitVec<B> {
/// Applies the given operation to the blocks of self and other, and sets
/// self to be the result. This relies on the caller not to corrupt the
/// last word.
#[inline]
fn process<F>(&mut self, other: &BitVec<B>, mut op: F) -> bool
where
F: FnMut(B, B) -> B,
{
assert_eq!(self.len(), other.len());
debug_assert_eq!(self.storage.len(), other.storage.len());
let mut changed_bits = B::zero();
for (a, b) in self.blocks_mut().zip(other.blocks()) {
let w = op(*a, b);
changed_bits = changed_bits | (*a ^ w);
*a = w;
}
changed_bits != B::zero()
}
/// Iterator over mutable refs to the underlying blocks of data.
#[inline]
fn blocks_mut(&mut self) -> MutBlocks<B> {
// (2)
self.storage.iter_mut()
}
/// Iterator over the underlying blocks of data
#[inline]
pub fn blocks(&self) -> Blocks<B> {
// (2)
Blocks {
iter: self.storage.iter(),
}
}
/// Exposes the raw block storage of this `BitVec`.
///
/// Only really intended for `BitSet`.
#[inline]
pub fn storage(&self) -> &[B] {
&self.storage
}
/// Exposes the raw block storage of this `BitVec`.
///
/// # Safety
///
/// Can probably cause unsafety. Only really intended for `BitSet`.
#[inline]
pub unsafe fn storage_mut(&mut self) -> &mut Vec<B> {
&mut self.storage
}
/// Helper for procedures involving spare space in the last block.
#[inline]
fn last_block_with_mask(&self) -> Option<(B, B)> {
let extra_bits = self.len() % B::bits();
if extra_bits > 0 {
let mask = (B::one() << extra_bits) - B::one();
let storage_len = self.storage.len();
Some((self.storage[storage_len - 1], mask))
} else {
None
}
}
/// Helper for procedures involving spare space in the last block.
#[inline]
fn last_block_mut_with_mask(&mut self) -> Option<(&mut B, B)> {
let extra_bits = self.len() % B::bits();
if extra_bits > 0 {
let mask = (B::one() << extra_bits) - B::one();
let storage_len = self.storage.len();
Some((&mut self.storage[storage_len - 1], mask))
} else {
None
}
}
/// An operation might screw up the unused bits in the last block of the
/// `BitVec`. As per (3), it's assumed to be all 0s. This method fixes it up.
fn fix_last_block(&mut self) {
if let Some((last_block, used_bits)) = self.last_block_mut_with_mask() {
*last_block = *last_block & used_bits;
}
}
/// Operations such as change detection for xnor, nor and nand are easiest
/// to implement when unused bits are all set to 1s.
fn fix_last_block_with_ones(&mut self) {
if let Some((last_block, used_bits)) = self.last_block_mut_with_mask() {
*last_block = *last_block | !used_bits;
}
}
/// Check whether last block's invariant is fine.
fn is_last_block_fixed(&self) -> bool {
if let Some((last_block, used_bits)) = self.last_block_with_mask() {
last_block & !used_bits == B::zero()
} else {
true
}
}
/// Ensure the invariant for the last block.
///
/// An operation might screw up the unused bits in the last block of the
/// `BitVec`.
///
/// This method fails in case the last block is not fixed. The check
/// is skipped outside testing.
#[inline]
fn ensure_invariant(&self) {
if cfg!(test) {
debug_assert!(self.is_last_block_fixed());
}
}
/// Retrieves the value at index `i`, or `None` if the index is out of bounds.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let bv = BitVec::from_bytes(&[0b01100000]);
/// assert_eq!(bv.get(0), Some(false));
/// assert_eq!(bv.get(1), Some(true));
/// assert_eq!(bv.get(100), None);
///
/// // Can also use array indexing
/// assert_eq!(bv[1], true);
/// ```
#[inline]
pub fn get(&self, i: usize) -> Option<bool> {
self.ensure_invariant();
if i >= self.nbits {
return None;
}
let w = i / B::bits();
let b = i % B::bits();
self.storage
.get(w)
.map(|&block| (block & (B::one() << b)) != B::zero())
}
/// Retrieves the value at index `i`, without doing bounds checking.
///
/// For a safe alternative, see `get`.
///
/// # Safety
///
/// Calling this method with an out-of-bounds index is undefined behavior
/// even if the resulting reference is not used.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let bv = BitVec::from_bytes(&[0b01100000]);
/// unsafe {
/// assert_eq!(bv.get_unchecked(0), false);
/// assert_eq!(bv.get_unchecked(1), true);
/// }
/// ```
#[inline]
pub unsafe fn get_unchecked(&self, i: usize) -> bool {
self.ensure_invariant();
let w = i / B::bits();
let b = i % B::bits();
let block = *self.storage.get_unchecked(w);
block & (B::one() << b) != B::zero()
}
/// Retrieves a smart pointer to the value at index `i`, or `None` if the index is out of bounds.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_bytes(&[0b01100000]);
/// *bv.get_mut(0).unwrap() = true;
/// *bv.get_mut(1).unwrap() = false;
/// assert!(bv.get_mut(100).is_none());
/// assert_eq!(bv, BitVec::from_bytes(&[0b10100000]));
/// ```
#[inline]
pub fn get_mut(&mut self, index: usize) -> Option<MutBorrowedBit<B>> {
self.get(index).map(move |value| MutBorrowedBit {
vec: Rc::new(RefCell::new(self)),
index,
#[cfg(debug_assertions)]
old_value: value,
new_value: value,
})
}
/// Retrieves a smart pointer to the value at index `i`, without doing bounds checking.
///
/// # Safety
///
/// Calling this method with out-of-bounds `index` may cause undefined behavior even when
/// the result is not used.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_bytes(&[0b01100000]);
/// unsafe {
/// *bv.get_unchecked_mut(0) = true;
/// *bv.get_unchecked_mut(1) = false;
/// }
/// assert_eq!(bv, BitVec::from_bytes(&[0b10100000]));
/// ```
#[inline]
pub unsafe fn get_unchecked_mut(&mut self, index: usize) -> MutBorrowedBit<B> {
let value = self.get_unchecked(index);
MutBorrowedBit {
#[cfg(debug_assertions)]
old_value: value,
new_value: value,
vec: Rc::new(RefCell::new(self)),
index,
}
}
/// Sets the value of a bit at an index `i`.
///
/// # Panics
///
/// Panics if `i` is out of bounds.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(5, false);
/// bv.set(3, true);
/// assert_eq!(bv[3], true);
/// ```
#[inline]
pub fn set(&mut self, i: usize, x: bool) {
self.ensure_invariant();
assert!(
i < self.nbits,
"index out of bounds: {:?} >= {:?}",
i,
self.nbits
);
let w = i / B::bits();
let b = i % B::bits();
let flag = B::one() << b;
let val = if x {
self.storage[w] | flag
} else {
self.storage[w] & !flag
};
self.storage[w] = val;
}
/// Sets all bits to 1.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let before = 0b01100000;
/// let after = 0b11111111;
///
/// let mut bv = BitVec::from_bytes(&[before]);
/// bv.set_all();
/// assert_eq!(bv, BitVec::from_bytes(&[after]));
/// ```
#[inline]
pub fn set_all(&mut self) {
self.ensure_invariant();
for w in &mut self.storage {
*w = !B::zero();
}
self.fix_last_block();
}
/// Flips all bits.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let before = 0b01100000;
/// let after = 0b10011111;
///
/// let mut bv = BitVec::from_bytes(&[before]);
/// bv.negate();
/// assert_eq!(bv, BitVec::from_bytes(&[after]));
/// ```
#[inline]
pub fn negate(&mut self) {
self.ensure_invariant();
for w in &mut self.storage {
*w = !*w;
}
self.fix_last_block();
}
/// Calculates the union of two bitvectors. This acts like the bitwise `or`
/// function.
///
/// Sets `self` to the union of `self` and `other`. Both bitvectors must be
/// the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different lengths.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let res = 0b01111110;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.union(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[deprecated(since = "0.7.0", note = "Please use the 'or' function instead")]
#[inline]
pub fn union(&mut self, other: &Self) -> bool {
self.or(other)
}
/// Calculates the intersection of two bitvectors. This acts like the
/// bitwise `and` function.
///
/// Sets `self` to the intersection of `self` and `other`. Both bitvectors
/// must be the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different lengths.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let res = 0b01000000;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.intersect(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[deprecated(since = "0.7.0", note = "Please use the 'and' function instead")]
#[inline]
pub fn intersect(&mut self, other: &Self) -> bool {
self.and(other)
}
/// Calculates the bitwise `or` of two bitvectors.
///
/// Sets `self` to the union of `self` and `other`. Both bitvectors must be
/// the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different lengths.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let res = 0b01111110;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.or(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[inline]
pub fn or(&mut self, other: &Self) -> bool {
self.ensure_invariant();
debug_assert!(other.is_last_block_fixed());
self.process(other, |w1, w2| (w1 | w2))
}
/// Calculates the bitwise `and` of two bitvectors.
///
/// Sets `self` to the intersection of `self` and `other`. Both bitvectors
/// must be the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different lengths.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let res = 0b01000000;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.and(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[inline]
pub fn and(&mut self, other: &Self) -> bool {
self.ensure_invariant();
debug_assert!(other.is_last_block_fixed());
self.process(other, |w1, w2| (w1 & w2))
}
/// Calculates the difference between two bitvectors.
///
/// Sets each element of `self` to the value of that element minus the
/// element of `other` at the same index. Both bitvectors must be the same
/// length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different length.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let a = 0b01100100;
/// let b = 0b01011010;
/// let a_b = 0b00100100; // a - b
/// let b_a = 0b00011010; // b - a
///
/// let mut bva = BitVec::from_bytes(&[a]);
/// let bvb = BitVec::from_bytes(&[b]);
///
/// assert!(bva.difference(&bvb));
/// assert_eq!(bva, BitVec::from_bytes(&[a_b]));
///
/// let bva = BitVec::from_bytes(&[a]);
/// let mut bvb = BitVec::from_bytes(&[b]);
///
/// assert!(bvb.difference(&bva));
/// assert_eq!(bvb, BitVec::from_bytes(&[b_a]));
/// ```
#[inline]
pub fn difference(&mut self, other: &Self) -> bool {
self.ensure_invariant();
debug_assert!(other.is_last_block_fixed());
self.process(other, |w1, w2| (w1 & !w2))
}
/// Calculates the xor of two bitvectors.
///
/// Sets `self` to the xor of `self` and `other`. Both bitvectors must be
/// the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different length.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let a = 0b01100110;
/// let b = 0b01010100;
/// let res = 0b00110010;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.xor(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[inline]
pub fn xor(&mut self, other: &Self) -> bool {
self.ensure_invariant();
debug_assert!(other.is_last_block_fixed());
self.process(other, |w1, w2| (w1 ^ w2))
}
/// Calculates the nand of two bitvectors.
///
/// Sets `self` to the nand of `self` and `other`. Both bitvectors must be
/// the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different length.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let a = 0b01100110;
/// let b = 0b01010100;
/// let res = 0b10111011;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.nand(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[inline]
pub fn nand(&mut self, other: &Self) -> bool {
self.ensure_invariant();
debug_assert!(other.is_last_block_fixed());
self.fix_last_block_with_ones();
let result = self.process(other, |w1, w2| !(w1 & w2));
self.fix_last_block();
result
}
/// Calculates the nor of two bitvectors.
///
/// Sets `self` to the nor of `self` and `other`. Both bitvectors must be
/// the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different length.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let a = 0b01100110;
/// let b = 0b01010100;
/// let res = 0b10001001;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.nor(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[inline]
pub fn nor(&mut self, other: &Self) -> bool {
self.ensure_invariant();
debug_assert!(other.is_last_block_fixed());
self.fix_last_block_with_ones();
let result = self.process(other, |w1, w2| !(w1 | w2));
self.fix_last_block();
result
}
/// Calculates the xnor of two bitvectors.
///
/// Sets `self` to the xnor of `self` and `other`. Both bitvectors must be
/// the same length. Returns `true` if `self` changed.
///
/// # Panics
///
/// Panics if the bitvectors are of different length.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let a = 0b01100110;
/// let b = 0b01010100;
/// let res = 0b11001101;
///
/// let mut a = BitVec::from_bytes(&[a]);
/// let b = BitVec::from_bytes(&[b]);
///
/// assert!(a.xnor(&b));
/// assert_eq!(a, BitVec::from_bytes(&[res]));
/// ```
#[inline]
pub fn xnor(&mut self, other: &Self) -> bool {
self.ensure_invariant();
debug_assert!(other.is_last_block_fixed());
self.fix_last_block_with_ones();
let result = self.process(other, |w1, w2| !(w1 ^ w2));
self.fix_last_block();
result
}
/// Returns `true` if all bits are 1.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(5, true);
/// assert_eq!(bv.all(), true);
///
/// bv.set(1, false);
/// assert_eq!(bv.all(), false);
/// ```
#[inline]
pub fn all(&self) -> bool {
self.ensure_invariant();
let mut last_word = !B::zero();
// Check that every block but the last is all-ones...
self.blocks().all(|elem| {
let tmp = last_word;
last_word = elem;
tmp == !B::zero()
// and then check the last one has enough ones
}) && (last_word == mask_for_bits(self.nbits))
}
/// Returns the number of ones in the binary representation.
///
/// Also known as the
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(100, true);
/// assert_eq!(bv.count_ones(), 100);
///
/// bv.set(50, false);
/// assert_eq!(bv.count_ones(), 99);
/// ```
#[inline]
pub fn count_ones(&self) -> u64 {
self.ensure_invariant();
// Add the number of ones of each block.
self.blocks().map(|elem| elem.count_ones() as u64).sum()
}
/// Returns the number of zeros in the binary representation.
///
/// Also known as the opposite of
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(100, false);
/// assert_eq!(bv.count_zeros(), 100);
///
/// bv.set(50, true);
/// assert_eq!(bv.count_zeros(), 99);
/// ```
#[inline]
pub fn count_zeros(&self) -> u64 {
self.ensure_invariant();
// Add the number of zeros of each block.
let extra_zeros = (B::bits() - (self.len() % B::bits())) % B::bits();
self.blocks()
.map(|elem| elem.count_zeros() as u64)
.sum::<u64>()
- extra_zeros as u64
}
/// Returns an iterator over the elements of the vector in order.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let bv = BitVec::from_bytes(&[0b01110100, 0b10010010]);
/// assert_eq!(bv.iter().filter(|x| *x).count(), 7);
/// ```
#[inline]
pub fn iter(&self) -> Iter<B> {
self.ensure_invariant();
Iter {
bit_vec: self,
range: 0..self.nbits,
}
}
/// Returns an iterator over mutable smart pointers to the elements of the vector in order.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut a = BitVec::from_elem(8, false);
/// a.iter_mut().enumerate().for_each(|(index, mut bit)| {
/// *bit = if index % 2 == 1 { true } else { false };
/// });
/// assert!(a.eq_vec(&[
/// false, true, false, true, false, true, false, true
/// ]));
/// ```
#[inline]
pub fn iter_mut(&mut self) -> IterMut<B> {
self.ensure_invariant();
let nbits = self.nbits;
IterMut {
vec: Rc::new(RefCell::new(self)),
range: 0..nbits,
}
}
/// Moves all bits from `other` into `Self`, leaving `other` empty.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut a = BitVec::from_bytes(&[0b10000000]);
/// let mut b = BitVec::from_bytes(&[0b01100001]);
///
/// a.append(&mut b);
///
/// assert_eq!(a.len(), 16);
/// assert_eq!(b.len(), 0);
/// assert!(a.eq_vec(&[true, false, false, false, false, false, false, false,
/// false, true, true, false, false, false, false, true]));
/// ```
pub fn append(&mut self, other: &mut Self) {
self.ensure_invariant();
debug_assert!(other.is_last_block_fixed());
let b = self.len() % B::bits();
let o = other.len() % B::bits();
let will_overflow = (b + o > B::bits()) || (o == 0 && b != 0);
self.nbits += other.len();
other.nbits = 0;
if b == 0 {
self.storage.append(&mut other.storage);
} else {
self.storage.reserve(other.storage.len());
for block in other.storage.drain(..) {
{
let last = self.storage.last_mut().unwrap();
*last = *last | (block << b);
}
self.storage.push(block >> (B::bits() - b));
}
// Remove additional block if the last shift did not overflow
if !will_overflow {
self.storage.pop();
}
}
}
/// Splits the `BitVec` into two at the given bit,
/// retaining the first half in-place and returning the second one.
///
/// # Panics
///
/// Panics if `at` is out of bounds.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
/// let mut a = BitVec::new();
/// a.push(true);
/// a.push(false);
/// a.push(false);
/// a.push(true);
///
/// let b = a.split_off(2);
///
/// assert_eq!(a.len(), 2);
/// assert_eq!(b.len(), 2);
/// assert!(a.eq_vec(&[true, false]));
/// assert!(b.eq_vec(&[false, true]));
/// ```
pub fn split_off(&mut self, at: usize) -> Self {
self.ensure_invariant();
assert!(at <= self.len(), "`at` out of bounds");
let mut other = BitVec::<B>::default();
if at == 0 {
mem::swap(self, &mut other);
return other;
} else if at == self.len() {
return other;
}
let w = at / B::bits();
let b = at % B::bits();
other.nbits = self.nbits - at;
self.nbits = at;
if b == 0 {
// Split at block boundary
other.storage = self.storage.split_off(w);
} else {
other.storage.reserve(self.storage.len() - w);
{
let mut iter = self.storage[w..].iter();
let mut last = *iter.next().unwrap();
for &cur in iter {
other.storage.push((last >> b) | (cur << (B::bits() - b)));
last = cur;
}
other.storage.push(last >> b);
}
self.storage.truncate(w + 1);
self.fix_last_block();
}
other
}
/// Returns `true` if all bits are 0.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(10, false);
/// assert_eq!(bv.none(), true);
///
/// bv.set(3, true);
/// assert_eq!(bv.none(), false);
/// ```
#[inline]
pub fn none(&self) -> bool {
self.blocks().all(|w| w == B::zero())
}
/// Returns `true` if any bit is 1.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(10, false);
/// assert_eq!(bv.any(), false);
///
/// bv.set(3, true);
/// assert_eq!(bv.any(), true);
/// ```
#[inline]
pub fn any(&self) -> bool {
!self.none()
}
/// Organises the bits into bytes, such that the first bit in the
/// `BitVec` becomes the high-order bit of the first byte. If the
/// size of the `BitVec` is not a multiple of eight then trailing bits
/// will be filled-in with `false`.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(3, true);
/// bv.set(1, false);
///
/// assert_eq!(bv.to_bytes(), [0b10100000]);
///
/// let mut bv = BitVec::from_elem(9, false);
/// bv.set(2, true);
/// bv.set(8, true);
///
/// assert_eq!(bv.to_bytes(), [0b00100000, 0b10000000]);
/// ```
pub fn to_bytes(&self) -> Vec<u8> {
self.ensure_invariant();
// Oh lord, we're mapping this to bytes bit-by-bit!
fn bit<B: BitBlock>(bit_vec: &BitVec<B>, byte: usize, bit: usize) -> u8 {
let offset = byte * 8 + bit;
if offset >= bit_vec.nbits {
0
} else {
(bit_vec[offset] as u8) << (7 - bit)
}
}
let len = self.nbits / 8 + if self.nbits % 8 == 0 { 0 } else { 1 };
(0..len)
.map(|i| {
bit(self, i, 0)
| bit(self, i, 1)
| bit(self, i, 2)
| bit(self, i, 3)
| bit(self, i, 4)
| bit(self, i, 5)
| bit(self, i, 6)
| bit(self, i, 7)
})
.collect()
}
/// Compares a `BitVec` to a slice of `bool`s.
/// Both the `BitVec` and slice must have the same length.
///
/// # Panics
///
/// Panics if the `BitVec` and slice are of different length.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let bv = BitVec::from_bytes(&[0b10100000]);
///
/// assert!(bv.eq_vec(&[true, false, true, false,
/// false, false, false, false]));
/// ```
#[inline]
pub fn eq_vec(&self, v: &[bool]) -> bool {
assert_eq!(self.nbits, v.len());
self.iter().zip(v.iter().cloned()).all(|(b1, b2)| b1 == b2)
}
/// Shortens a `BitVec`, dropping excess elements.
///
/// If `len` is greater than the vector's current length, this has no
/// effect.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_bytes(&[0b01001011]);
/// bv.truncate(2);
/// assert!(bv.eq_vec(&[false, true]));
/// ```
#[inline]
pub fn truncate(&mut self, len: usize) {
self.ensure_invariant();
if len < self.len() {
self.nbits = len;
// This fixes (2).
self.storage.truncate(blocks_for_bits::<B>(len));
self.fix_last_block();
}
}
/// Reserves capacity for at least `additional` more bits to be inserted in the given
/// `BitVec`. The collection may reserve more space to avoid frequent reallocations.
///
/// # Panics
///
/// Panics if the new capacity overflows `usize`.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(3, false);
/// bv.reserve(10);
/// assert_eq!(bv.len(), 3);
/// assert!(bv.capacity() >= 13);
/// ```
#[inline]
pub fn reserve(&mut self, additional: usize) {
let desired_cap = self
.len()
.checked_add(additional)
.expect("capacity overflow");
let storage_len = self.storage.len();
if desired_cap > self.capacity() {
self.storage
.reserve(blocks_for_bits::<B>(desired_cap) - storage_len);
}
}
/// Reserves the minimum capacity for exactly `additional` more bits to be inserted in the
/// given `BitVec`. Does nothing if the capacity is already sufficient.
///
/// 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` if future
/// insertions are expected.
///
/// # Panics
///
/// Panics if the new capacity overflows `usize`.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_elem(3, false);
/// bv.reserve(10);
/// assert_eq!(bv.len(), 3);
/// assert!(bv.capacity() >= 13);
/// ```
#[inline]
pub fn reserve_exact(&mut self, additional: usize) {
let desired_cap = self
.len()
.checked_add(additional)
.expect("capacity overflow");
let storage_len = self.storage.len();
if desired_cap > self.capacity() {
self.storage
.reserve_exact(blocks_for_bits::<B>(desired_cap) - storage_len);
}
}
/// Returns the capacity in bits for this bit vector. Inserting any
/// element less than this amount will not trigger a resizing.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::new();
/// bv.reserve(10);
/// assert!(bv.capacity() >= 10);
/// ```
#[inline]
pub fn capacity(&self) -> usize {
self.storage.capacity().saturating_mul(B::bits())
}
/// Grows the `BitVec` in-place, adding `n` copies of `value` to the `BitVec`.
///
/// # Panics
///
/// Panics if the new len overflows a `usize`.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_bytes(&[0b01001011]);
/// bv.grow(2, true);
/// assert_eq!(bv.len(), 10);
/// assert_eq!(bv.to_bytes(), [0b01001011, 0b11000000]);
/// ```
pub fn grow(&mut self, n: usize, value: bool) {
self.ensure_invariant();
// Note: we just bulk set all the bits in the last word in this fn in multiple places
// which is technically wrong if not all of these bits are to be used. However, at the end
// of this fn we call `fix_last_block` at the end of this fn, which should fix this.
let new_nbits = self.nbits.checked_add(n).expect("capacity overflow");
let new_nblocks = blocks_for_bits::<B>(new_nbits);
let full_value = if value { !B::zero() } else { B::zero() };
// Correct the old tail word, setting or clearing formerly unused bits
let num_cur_blocks = blocks_for_bits::<B>(self.nbits);
if self.nbits % B::bits() > 0 {
let mask = mask_for_bits::<B>(self.nbits);
if value {
let block = &mut self.storage[num_cur_blocks - 1];
*block = *block | !mask;
} else {
// Extra bits are already zero by invariant.
}
}
// Fill in words after the old tail word
let stop_idx = cmp::min(self.storage.len(), new_nblocks);
for idx in num_cur_blocks..stop_idx {
self.storage[idx] = full_value;
}
// Allocate new words, if needed
if new_nblocks > self.storage.len() {
let to_add = new_nblocks - self.storage.len();
self.storage.extend(repeat(full_value).take(to_add));
}
// Adjust internal bit count
self.nbits = new_nbits;
self.fix_last_block();
}
/// Removes the last bit from the `BitVec`, and returns it. Returns `None` if the `BitVec` is empty.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::from_bytes(&[0b01001001]);
/// assert_eq!(bv.pop(), Some(true));
/// assert_eq!(bv.pop(), Some(false));
/// assert_eq!(bv.len(), 6);
/// ```
#[inline]
pub fn pop(&mut self) -> Option<bool> {
self.ensure_invariant();
if self.is_empty() {
None
} else {
let i = self.nbits - 1;
let ret = self[i];
// (3)
self.set(i, false);
self.nbits = i;
if self.nbits % B::bits() == 0 {
// (2)
self.storage.pop();
}
Some(ret)
}
}
/// Pushes a `bool` onto the end.
///
/// # Examples
///
/// ```
/// use bit_vec::BitVec;
///
/// let mut bv = BitVec::new();
/// bv.push(true);
/// bv.push(false);
/// assert!(bv.eq_vec(&[true, false]));
/// ```
#[inline]
pub fn push(&mut self, elem: bool) {
if self.nbits % B::bits() == 0 {
self.storage.push(B::zero());
}
let insert_pos = self.nbits;
self.nbits = self.nbits.checked_add(1).expect("Capacity overflow");
self.set(insert_pos, elem);
}
/// Returns the total number of bits in this vector
#[inline]
pub fn len(&self) -> usize {
self.nbits
}
/// Sets the number of bits that this `BitVec` considers initialized.
///
/// # Safety
///
/// Almost certainly can cause bad stuff. Only really intended for `BitSet`.
#[inline]
pub unsafe fn set_len(&mut self, len: usize) {
self.nbits = len;
}
/// Returns true if there are no bits in this vector
#[inline]
pub fn is_empty(&self) -> bool {
self.len() == 0
}
/// Clears all bits in this vector.
#[inline]
pub fn clear(&mut self) {
self.ensure_invariant();
for w in &mut self.storage {
*w = B::zero();
}
}
/// Shrinks the capacity of the underlying storage as much as
/// possible.
///
/// It will drop down as close as possible to the length but the
/// allocator may still inform the underlying storage that there
/// is space for a few more elements/bits.
pub fn shrink_to_fit(&mut self) {
self.storage.shrink_to_fit();
}
/// Inserts a given bit at index `at`, shifting all bits after by one
///
/// # Panics
/// Panics if `at` is out of bounds for `BitVec`'s length (that is, if `at > BitVec::len()`)
///
/// # Examples
///```
/// use bit_vec::BitVec;
///
/// let mut b = BitVec::new();
///
/// b.push(true);
/// b.push(true);
/// b.insert(1, false);
///
/// assert!(b.eq_vec(&[true, false, true]));
///```
///
/// # Time complexity
/// Takes O([`len`]) time. All items after the insertion index must be
/// shifted to the right. In the worst case, all elements are shifted when
/// the insertion index is 0.
///
/// [`len`]: Self::len
pub fn insert(&mut self, at: usize, bit: bool) {
assert!(
at <= self.nbits,
"insertion index (is {at}) should be <= nbits (is {nbits})",
nbits = self.nbits
);
let last_block_bits = self.nbits % B::bits();
let block_at = at / B::bits(); // needed block
let bit_at = at % B::bits(); // index within the block
if last_block_bits == 0 {
self.storage.push(B::zero());
}
self.nbits += 1;
let mut carry = self.storage[block_at] >> (B::bits() - 1);
let lsbits_mask = (B::one() << bit_at) - B::one();
let set_bit = if bit { B::one() } else { B::zero() } << bit_at;
self.storage[block_at] = (self.storage[block_at] & lsbits_mask)
| ((self.storage[block_at] & !lsbits_mask) << 1)
| set_bit;
for block_ref in &mut self.storage[block_at + 1..] {
let curr_carry = *block_ref >> (B::bits() - 1);
*block_ref = *block_ref << 1 | carry;
carry = curr_carry;
}
}
}
impl<B: BitBlock> Default for BitVec<B> {
#[inline]
fn default() -> Self {
BitVec {
storage: Vec::new(),
nbits: 0,
}
}
}
impl<B: BitBlock> FromIterator<bool> for BitVec<B> {
#[inline]
fn from_iter<I: IntoIterator<Item = bool>>(iter: I) -> Self {
let mut ret: Self = Default::default();
ret.extend(iter);
ret
}
}
impl<B: BitBlock> Extend<bool> for BitVec<B> {
#[inline]
fn extend<I: IntoIterator<Item = bool>>(&mut self, iterable: I) {
self.ensure_invariant();
let iterator = iterable.into_iter();
let (min, _) = iterator.size_hint();
self.reserve(min);
for element in iterator {
self.push(element)
}
}
}
impl<B: BitBlock> Clone for BitVec<B> {
#[inline]
fn clone(&self) -> Self {
self.ensure_invariant();
BitVec {
storage: self.storage.clone(),
nbits: self.nbits,
}
}
#[inline]
fn clone_from(&mut self, source: &Self) {
debug_assert!(source.is_last_block_fixed());
self.nbits = source.nbits;
self.storage.clone_from(&source.storage);
}
}
impl<B: BitBlock> PartialOrd for BitVec<B> {
#[inline]
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl<B: BitBlock> Ord for BitVec<B> {
#[inline]
fn cmp(&self, other: &Self) -> Ordering {
self.ensure_invariant();
debug_assert!(other.is_last_block_fixed());
let mut a = self.iter();
let mut b = other.iter();
loop {
match (a.next(), b.next()) {
(Some(x), Some(y)) => match x.cmp(&y) {
Ordering::Equal => {}
otherwise => return otherwise,
},
(None, None) => return Ordering::Equal,
(None, _) => return Ordering::Less,
(_, None) => return Ordering::Greater,
}
}
}
}
impl<B: BitBlock> fmt::Display for BitVec<B> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
self.ensure_invariant();
for bit in self {
fmt.write_char(if bit { '1' } else { '0' })?;
}
Ok(())
}
}
impl<B: BitBlock> fmt::Debug for BitVec<B> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
self.ensure_invariant();
let mut storage = String::with_capacity(self.len() + self.len() / B::bits());
for (i, bit) in self.iter().enumerate() {
if i != 0 && i % B::bits() == 0 {
storage.push(' ');
}
storage.push(if bit { '1' } else { '0' });
}
fmt.debug_struct("BitVec")
.field("storage", &storage)
.field("nbits", &self.nbits)
.finish()
}
}
impl<B: BitBlock> hash::Hash for BitVec<B> {
#[inline]
fn hash<H: hash::Hasher>(&self, state: &mut H) {
self.ensure_invariant();
self.nbits.hash(state);
for elem in self.blocks() {
elem.hash(state);
}
}
}
impl<B: BitBlock> cmp::PartialEq for BitVec<B> {
#[inline]
fn eq(&self, other: &Self) -> bool {
if self.nbits != other.nbits {
self.ensure_invariant();
other.ensure_invariant();
return false;
}
self.blocks().zip(other.blocks()).all(|(w1, w2)| w1 == w2)
}
}
impl<B: BitBlock> cmp::Eq for BitVec<B> {}
/// An iterator for `BitVec`.
#[derive(Clone)]
pub struct Iter<'a, B: 'a = u32> {
bit_vec: &'a BitVec<B>,
range: Range<usize>,
}
#[derive(Debug)]
pub struct MutBorrowedBit<'a, B: 'a + BitBlock> {
vec: Rc<RefCell<&'a mut BitVec<B>>>,
index: usize,
#[cfg(debug_assertions)]
old_value: bool,
new_value: bool,
}
/// An iterator for mutable references to the bits in a `BitVec`.
pub struct IterMut<'a, B: 'a + BitBlock = u32> {
vec: Rc<RefCell<&'a mut BitVec<B>>>,
range: Range<usize>,
}
impl<'a, B: 'a + BitBlock> IterMut<'a, B> {
fn get(&mut self, index: Option<usize>) -> Option<MutBorrowedBit<'a, B>> {
let index = index?;
let value = (*self.vec).borrow().get(index)?;
Some(MutBorrowedBit {
vec: self.vec.clone(),
index,
#[cfg(debug_assertions)]
old_value: value,
new_value: value,
})
}
}
impl<'a, B: BitBlock> Deref for MutBorrowedBit<'a, B> {
type Target = bool;
fn deref(&self) -> &Self::Target {
&self.new_value
}
}
impl<'a, B: BitBlock> DerefMut for MutBorrowedBit<'a, B> {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.new_value
}
}
impl<'a, B: BitBlock> Drop for MutBorrowedBit<'a, B> {
fn drop(&mut self) {
let mut vec = (*self.vec).borrow_mut();
#[cfg(debug_assertions)]
debug_assert_eq!(
Some(self.old_value),
vec.get(self.index),
"Mutably-borrowed bit was modified externally!"
);
vec.set(self.index, self.new_value);
}
}
impl<'a, B: BitBlock> Iterator for Iter<'a, B> {
type Item = bool;
#[inline]
fn next(&mut self) -> Option<bool> {
// NB: indexing is slow for extern crates when it has to go through &TRUE or &FALSE
// variables. get is more direct, and unwrap is fine since we're sure of the range.
self.range.next().map(|i| self.bit_vec.get(i).unwrap())
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.range.size_hint()
}
}
impl<'a, B: BitBlock> Iterator for IterMut<'a, B> {
type Item = MutBorrowedBit<'a, B>;
#[inline]
fn next(&mut self) -> Option<Self::Item> {
let index = self.range.next();
self.get(index)
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.range.size_hint()
}
}
impl<'a, B: BitBlock> DoubleEndedIterator for Iter<'a, B> {
#[inline]
fn next_back(&mut self) -> Option<bool> {
self.range.next_back().map(|i| self.bit_vec.get(i).unwrap())
}
}
impl<'a, B: BitBlock> DoubleEndedIterator for IterMut<'a, B> {
#[inline]
fn next_back(&mut self) -> Option<Self::Item> {
let index = self.range.next_back();
self.get(index)
}
}
impl<'a, B: BitBlock> ExactSizeIterator for Iter<'a, B> {}
impl<'a, B: BitBlock> ExactSizeIterator for IterMut<'a, B> {}
impl<'a, B: BitBlock> IntoIterator for &'a BitVec<B> {
type Item = bool;
type IntoIter = Iter<'a, B>;
#[inline]
fn into_iter(self) -> Iter<'a, B> {
self.iter()
}
}
pub struct IntoIter<B = u32> {
bit_vec: BitVec<B>,
range: Range<usize>,
}
impl<B: BitBlock> Iterator for IntoIter<B> {
type Item = bool;
#[inline]
fn next(&mut self) -> Option<bool> {
self.range.next().map(|i| self.bit_vec.get(i).unwrap())
}
}
impl<B: BitBlock> DoubleEndedIterator for IntoIter<B> {
#[inline]
fn next_back(&mut self) -> Option<bool> {
self.range.next_back().map(|i| self.bit_vec.get(i).unwrap())
}
}
impl<B: BitBlock> ExactSizeIterator for IntoIter<B> {}
impl<B: BitBlock> IntoIterator for BitVec<B> {
type Item = bool;
type IntoIter = IntoIter<B>;
#[inline]
fn into_iter(self) -> IntoIter<B> {
let nbits = self.nbits;
IntoIter {
bit_vec: self,
range: 0..nbits,
}
}
}
/// An iterator over the blocks of a `BitVec`.
#[derive(Clone)]
pub struct Blocks<'a, B: 'a> {
iter: slice::Iter<'a, B>,
}
impl<'a, B: BitBlock> Iterator for Blocks<'a, B> {
type Item = B;
#[inline]
fn next(&mut self) -> Option<B> {
self.iter.next().cloned()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<'a, B: BitBlock> DoubleEndedIterator for Blocks<'a, B> {
#[inline]
fn next_back(&mut self) -> Option<B> {
self.iter.next_back().cloned()
}
}
impl<'a, B: BitBlock> ExactSizeIterator for Blocks<'a, B> {}
#[cfg(test)]
mod tests {
use super::{BitVec, Iter, Vec};
// This is stupid, but I want to differentiate from a "random" 32
const U32_BITS: usize = 32;
#[test]
fn test_display_output() {
assert_eq!(format!("{}", BitVec::new()), "");
assert_eq!(format!("{}", BitVec::from_elem(1, true)), "1");
assert_eq!(format!("{}", BitVec::from_elem(8, false)), "00000000")
}
#[test]
fn test_debug_output() {
assert_eq!(
format!("{:?}", BitVec::new()),
"BitVec { storage: \"\", nbits: 0 }"
);
assert_eq!(
format!("{:?}", BitVec::from_elem(1, true)),
"BitVec { storage: \"1\", nbits: 1 }"
);
assert_eq!(
format!("{:?}", BitVec::from_elem(8, false)),
"BitVec { storage: \"00000000\", nbits: 8 }"
);
assert_eq!(
format!("{:?}", BitVec::from_elem(33, true)),
"BitVec { storage: \"11111111111111111111111111111111 1\", nbits: 33 }"
);
assert_eq!(
format!(
"{:?}",
BitVec::from_bytes(&[0b111, 0b000, 0b1110, 0b0001, 0b11111111, 0b00000000])
),
"BitVec { storage: \"00000111000000000000111000000001 1111111100000000\", nbits: 48 }"
)
}
#[test]
fn test_0_elements() {
let act = BitVec::new();
let exp = Vec::new();
assert!(act.eq_vec(&exp));
assert!(act.none() && act.all());
}
#[test]
fn test_1_element() {
let mut act = BitVec::from_elem(1, false);
assert!(act.eq_vec(&[false]));
assert!(act.none() && !act.all());
act = BitVec::from_elem(1, true);
assert!(act.eq_vec(&[true]));
assert!(!act.none() && act.all());
}
#[test]
fn test_2_elements() {
let mut b = BitVec::from_elem(2, false);
b.set(0, true);
b.set(1, false);
assert_eq!(format!("{}", b), "10");
assert!(!b.none() && !b.all());
}
#[test]
fn test_10_elements() {
// all 0
let mut act = BitVec::from_elem(10, false);
assert!(
(act.eq_vec(&[false, false, false, false, false, false, false, false, false, false]))
);
assert!(act.none() && !act.all());
// all 1
act = BitVec::from_elem(10, true);
assert!((act.eq_vec(&[true, true, true, true, true, true, true, true, true, true])));
assert!(!act.none() && act.all());
// mixed
act = BitVec::from_elem(10, false);
act.set(0, true);
act.set(1, true);
act.set(2, true);
act.set(3, true);
act.set(4, true);
assert!((act.eq_vec(&[true, true, true, true, true, false, false, false, false, false])));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(10, false);
act.set(5, true);
act.set(6, true);
act.set(7, true);
act.set(8, true);
act.set(9, true);
assert!((act.eq_vec(&[false, false, false, false, false, true, true, true, true, true])));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(10, false);
act.set(0, true);
act.set(3, true);
act.set(6, true);
act.set(9, true);
assert!((act.eq_vec(&[true, false, false, true, false, false, true, false, false, true])));
assert!(!act.none() && !act.all());
}
#[test]
fn test_31_elements() {
// all 0
let mut act = BitVec::from_elem(31, false);
assert!(act.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false
]));
assert!(act.none() && !act.all());
// all 1
act = BitVec::from_elem(31, true);
assert!(act.eq_vec(&[
true, true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true
]));
assert!(!act.none() && act.all());
// mixed
act = BitVec::from_elem(31, false);
act.set(0, true);
act.set(1, true);
act.set(2, true);
act.set(3, true);
act.set(4, true);
act.set(5, true);
act.set(6, true);
act.set(7, true);
assert!(act.eq_vec(&[
true, true, true, true, true, true, true, true, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false
]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(31, false);
act.set(16, true);
act.set(17, true);
act.set(18, true);
act.set(19, true);
act.set(20, true);
act.set(21, true);
act.set(22, true);
act.set(23, true);
assert!(act.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, true, true, true, true, true, true, true, true, false,
false, false, false, false, false, false
]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(31, false);
act.set(24, true);
act.set(25, true);
act.set(26, true);
act.set(27, true);
act.set(28, true);
act.set(29, true);
act.set(30, true);
assert!(act.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
true, true, true, true, true, true, true
]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(31, false);
act.set(3, true);
act.set(17, true);
act.set(30, true);
assert!(act.eq_vec(&[
false, false, false, true, false, false, false, false, false, false, false, false,
false, false, false, false, false, true, false, false, false, false, false, false,
false, false, false, false, false, false, true
]));
assert!(!act.none() && !act.all());
}
#[test]
fn test_32_elements() {
// all 0
let mut act = BitVec::from_elem(32, false);
assert!(act.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false
]));
assert!(act.none() && !act.all());
// all 1
act = BitVec::from_elem(32, true);
assert!(act.eq_vec(&[
true, true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true
]));
assert!(!act.none() && act.all());
// mixed
act = BitVec::from_elem(32, false);
act.set(0, true);
act.set(1, true);
act.set(2, true);
act.set(3, true);
act.set(4, true);
act.set(5, true);
act.set(6, true);
act.set(7, true);
assert!(act.eq_vec(&[
true, true, true, true, true, true, true, true, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false
]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(32, false);
act.set(16, true);
act.set(17, true);
act.set(18, true);
act.set(19, true);
act.set(20, true);
act.set(21, true);
act.set(22, true);
act.set(23, true);
assert!(act.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, true, true, true, true, true, true, true, true, false,
false, false, false, false, false, false, false
]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(32, false);
act.set(24, true);
act.set(25, true);
act.set(26, true);
act.set(27, true);
act.set(28, true);
act.set(29, true);
act.set(30, true);
act.set(31, true);
assert!(act.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
true, true, true, true, true, true, true, true
]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(32, false);
act.set(3, true);
act.set(17, true);
act.set(30, true);
act.set(31, true);
assert!(act.eq_vec(&[
false, false, false, true, false, false, false, false, false, false, false, false,
false, false, false, false, false, true, false, false, false, false, false, false,
false, false, false, false, false, false, true, true
]));
assert!(!act.none() && !act.all());
}
#[test]
fn test_33_elements() {
// all 0
let mut act = BitVec::from_elem(33, false);
assert!(act.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false
]));
assert!(act.none() && !act.all());
// all 1
act = BitVec::from_elem(33, true);
assert!(act.eq_vec(&[
true, true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true, true, true, true, true, true, true, true, true, true,
true, true, true, true, true
]));
assert!(!act.none() && act.all());
// mixed
act = BitVec::from_elem(33, false);
act.set(0, true);
act.set(1, true);
act.set(2, true);
act.set(3, true);
act.set(4, true);
act.set(5, true);
act.set(6, true);
act.set(7, true);
assert!(act.eq_vec(&[
true, true, true, true, true, true, true, true, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false
]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(33, false);
act.set(16, true);
act.set(17, true);
act.set(18, true);
act.set(19, true);
act.set(20, true);
act.set(21, true);
act.set(22, true);
act.set(23, true);
assert!(act.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, true, true, true, true, true, true, true, true, false,
false, false, false, false, false, false, false, false
]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(33, false);
act.set(24, true);
act.set(25, true);
act.set(26, true);
act.set(27, true);
act.set(28, true);
act.set(29, true);
act.set(30, true);
act.set(31, true);
assert!(act.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
true, true, true, true, true, true, true, true, false
]));
assert!(!act.none() && !act.all());
// mixed
act = BitVec::from_elem(33, false);
act.set(3, true);
act.set(17, true);
act.set(30, true);
act.set(31, true);
act.set(32, true);
assert!(act.eq_vec(&[
false, false, false, true, false, false, false, false, false, false, false, false,
false, false, false, false, false, true, false, false, false, false, false, false,
false, false, false, false, false, false, true, true, true
]));
assert!(!act.none() && !act.all());
}
#[test]
fn test_equal_differing_sizes() {
let v0 = BitVec::from_elem(10, false);
let v1 = BitVec::from_elem(11, false);
assert_ne!(v0, v1);
}
#[test]
fn test_equal_greatly_differing_sizes() {
let v0 = BitVec::from_elem(10, false);
let v1 = BitVec::from_elem(110, false);
assert_ne!(v0, v1);
}
#[test]
fn test_equal_sneaky_small() {
let mut a = BitVec::from_elem(1, false);
a.set(0, true);
let mut b = BitVec::from_elem(1, true);
b.set(0, true);
assert_eq!(a, b);
}
#[test]
fn test_equal_sneaky_big() {
let mut a = BitVec::from_elem(100, false);
for i in 0..100 {
a.set(i, true);
}
let mut b = BitVec::from_elem(100, true);
for i in 0..100 {
b.set(i, true);
}
assert_eq!(a, b);
}
#[test]
fn test_from_bytes() {
let bit_vec = BitVec::from_bytes(&[0b10110110, 0b00000000, 0b11111111]);
let str = concat!("10110110", "00000000", "11111111");
assert_eq!(format!("{}", bit_vec), str);
}
#[test]
fn test_to_bytes() {
let mut bv = BitVec::from_elem(3, true);
bv.set(1, false);
assert_eq!(bv.to_bytes(), [0b10100000]);
let mut bv = BitVec::from_elem(9, false);
bv.set(2, true);
bv.set(8, true);
assert_eq!(bv.to_bytes(), [0b00100000, 0b10000000]);
}
#[test]
fn test_from_bools() {
let bools = [true, false, true, true];
let bit_vec: BitVec = bools.iter().copied().collect();
assert_eq!(format!("{}", bit_vec), "1011");
}
#[test]
fn test_to_bools() {
let bools = vec![false, false, true, false, false, true, true, false];
assert_eq!(
BitVec::from_bytes(&[0b00100110])
.iter()
.collect::<Vec<bool>>(),
bools
);
}
#[test]
fn test_bit_vec_iterator() {
let bools = vec![true, false, true, true];
let bit_vec: BitVec = bools.iter().copied().collect();
assert_eq!(bit_vec.iter().collect::<Vec<bool>>(), bools);
let long: Vec<_> = (0..10000).map(|i| i % 2 == 0).collect();
let bit_vec: BitVec = long.iter().copied().collect();
assert_eq!(bit_vec.iter().collect::<Vec<bool>>(), long)
}
#[test]
fn test_small_difference() {
let mut b1 = BitVec::from_elem(3, false);
let mut b2 = BitVec::from_elem(3, false);
b1.set(0, true);
b1.set(1, true);
b2.set(1, true);
b2.set(2, true);
assert!(b1.difference(&b2));
assert!(b1[0]);
assert!(!b1[1]);
assert!(!b1[2]);
}
#[test]
fn test_big_difference() {
let mut b1 = BitVec::from_elem(100, false);
let mut b2 = BitVec::from_elem(100, false);
b1.set(0, true);
b1.set(40, true);
b2.set(40, true);
b2.set(80, true);
assert!(b1.difference(&b2));
assert!(b1[0]);
assert!(!b1[40]);
assert!(!b1[80]);
}
#[test]
fn test_small_xor() {
let mut a = BitVec::from_bytes(&[0b0011]);
let b = BitVec::from_bytes(&[0b0101]);
let c = BitVec::from_bytes(&[0b0110]);
assert!(a.xor(&b));
assert_eq!(a, c);
}
#[test]
fn test_small_xnor() {
let mut a = BitVec::from_bytes(&[0b0011]);
let b = BitVec::from_bytes(&[0b1111_0101]);
let c = BitVec::from_bytes(&[0b1001]);
assert!(a.xnor(&b));
assert_eq!(a, c);
}
#[test]
fn test_small_nand() {
let mut a = BitVec::from_bytes(&[0b1111_0011]);
let b = BitVec::from_bytes(&[0b1111_0101]);
let c = BitVec::from_bytes(&[0b1110]);
assert!(a.nand(&b));
assert_eq!(a, c);
}
#[test]
fn test_small_nor() {
let mut a = BitVec::from_bytes(&[0b0011]);
let b = BitVec::from_bytes(&[0b1111_0101]);
let c = BitVec::from_bytes(&[0b1000]);
assert!(a.nor(&b));
assert_eq!(a, c);
}
#[test]
fn test_big_xor() {
let mut a = BitVec::from_bytes(&[
// 88 bits
0, 0, 0b00010100, 0, 0, 0, 0, 0b00110100, 0, 0, 0,
]);
let b = BitVec::from_bytes(&[
// 88 bits
0, 0, 0b00010100, 0, 0, 0, 0, 0, 0, 0, 0b00110100,
]);
let c = BitVec::from_bytes(&[
// 88 bits
0, 0, 0, 0, 0, 0, 0, 0b00110100, 0, 0, 0b00110100,
]);
assert!(a.xor(&b));
assert_eq!(a, c);
}
#[test]
fn test_big_xnor() {
let mut a = BitVec::from_bytes(&[
// 88 bits
0, 0, 0b00010100, 0, 0, 0, 0, 0b00110100, 0, 0, 0,
]);
let b = BitVec::from_bytes(&[
// 88 bits
0, 0, 0b00010100, 0, 0, 0, 0, 0, 0, 0, 0b00110100,
]);
let c = BitVec::from_bytes(&[
// 88 bits
!0,
!0,
!0,
!0,
!0,
!0,
!0,
!0b00110100,
!0,
!0,
!0b00110100,
]);
assert!(a.xnor(&b));
assert_eq!(a, c);
}
#[test]
fn test_small_clear() {
let mut b = BitVec::from_elem(14, true);
assert!(!b.none() && b.all());
b.clear();
assert!(b.none() && !b.all());
}
#[test]
fn test_big_clear() {
let mut b = BitVec::from_elem(140, true);
assert!(!b.none() && b.all());
b.clear();
assert!(b.none() && !b.all());
}
#[test]
fn test_bit_vec_lt() {
let mut a = BitVec::from_elem(5, false);
let mut b = BitVec::from_elem(5, false);
assert!(a >= b && b >= a);
b.set(2, true);
assert!(a < b);
a.set(3, true);
assert!(a < b);
a.set(2, true);
assert!(a >= b && b < a);
b.set(0, true);
assert!(a < b);
}
#[test]
fn test_ord() {
let mut a = BitVec::from_elem(5, false);
let mut b = BitVec::from_elem(5, false);
assert!(a == b);
a.set(1, true);
assert!(a > b && a >= b);
assert!(b < a && b <= a);
b.set(1, true);
b.set(2, true);
assert!(b > a && b >= a);
assert!(a < b && a <= b);
}
#[test]
fn test_small_bit_vec_tests() {
let v = BitVec::from_bytes(&[0]);
assert!(!v.all());
assert!(!v.any());
assert!(v.none());
let v = BitVec::from_bytes(&[0b00010100]);
assert!(!v.all());
assert!(v.any());
assert!(!v.none());
let v = BitVec::from_bytes(&[0xFF]);
assert!(v.all());
assert!(v.any());
assert!(!v.none());
}
#[test]
fn test_big_bit_vec_tests() {
let v = BitVec::from_bytes(&[
// 88 bits
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
]);
assert!(!v.all());
assert!(!v.any());
assert!(v.none());
let v = BitVec::from_bytes(&[
// 88 bits
0, 0, 0b00010100, 0, 0, 0, 0, 0b00110100, 0, 0, 0,
]);
assert!(!v.all());
assert!(v.any());
assert!(!v.none());
let v = BitVec::from_bytes(&[
// 88 bits
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
]);
assert!(v.all());
assert!(v.any());
assert!(!v.none());
}
#[test]
fn test_bit_vec_push_pop() {
let mut s = BitVec::from_elem(5 * U32_BITS - 2, false);
assert_eq!(s.len(), 5 * U32_BITS - 2);
assert!(!s[5 * U32_BITS - 3]);
s.push(true);
s.push(true);
assert!(s[5 * U32_BITS - 2]);
assert!(s[5 * U32_BITS - 1]);
// Here the internal vector will need to be extended
s.push(false);
assert!(!s[5 * U32_BITS]);
s.push(false);
assert!(!s[5 * U32_BITS + 1]);
assert_eq!(s.len(), 5 * U32_BITS + 2);
// Pop it all off
assert_eq!(s.pop(), Some(false));
assert_eq!(s.pop(), Some(false));
assert_eq!(s.pop(), Some(true));
assert_eq!(s.pop(), Some(true));
assert_eq!(s.len(), 5 * U32_BITS - 2);
}
#[test]
fn test_bit_vec_truncate() {
let mut s = BitVec::from_elem(5 * U32_BITS, true);
assert_eq!(s, BitVec::from_elem(5 * U32_BITS, true));
assert_eq!(s.len(), 5 * U32_BITS);
s.truncate(4 * U32_BITS);
assert_eq!(s, BitVec::from_elem(4 * U32_BITS, true));
assert_eq!(s.len(), 4 * U32_BITS);
// Truncating to a size > s.len() should be a noop
s.truncate(5 * U32_BITS);
assert_eq!(s, BitVec::from_elem(4 * U32_BITS, true));
assert_eq!(s.len(), 4 * U32_BITS);
s.truncate(3 * U32_BITS - 10);
assert_eq!(s, BitVec::from_elem(3 * U32_BITS - 10, true));
assert_eq!(s.len(), 3 * U32_BITS - 10);
s.truncate(0);
assert_eq!(s, BitVec::from_elem(0, true));
assert_eq!(s.len(), 0);
}
#[test]
fn test_bit_vec_reserve() {
let mut s = BitVec::from_elem(5 * U32_BITS, true);
// Check capacity
assert!(s.capacity() >= 5 * U32_BITS);
s.reserve(2 * U32_BITS);
assert!(s.capacity() >= 7 * U32_BITS);
s.reserve(7 * U32_BITS);
assert!(s.capacity() >= 12 * U32_BITS);
s.reserve_exact(7 * U32_BITS);
assert!(s.capacity() >= 12 * U32_BITS);
s.reserve(7 * U32_BITS + 1);
assert!(s.capacity() > 12 * U32_BITS);
// Check that length hasn't changed
assert_eq!(s.len(), 5 * U32_BITS);
s.push(true);
s.push(false);
s.push(true);
assert!(s[5 * U32_BITS - 1]);
assert!(s[5 * U32_BITS]);
assert!(!s[5 * U32_BITS + 1]);
assert!(s[5 * U32_BITS + 2]);
}
#[test]
fn test_bit_vec_grow() {
let mut bit_vec = BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010]);
bit_vec.grow(32, true);
assert_eq!(
bit_vec,
BitVec::from_bytes(&[0b10110110, 0b00000000, 0b10101010, 0xFF, 0xFF, 0xFF, 0xFF])
);
bit_vec.grow(64, false);
assert_eq!(
bit_vec,
BitVec::from_bytes(&[
0b10110110, 0b00000000, 0b10101010, 0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0
])
);
bit_vec.grow(16, true);
assert_eq!(
bit_vec,
BitVec::from_bytes(&[
0b10110110, 0b00000000, 0b10101010, 0xFF, 0xFF, 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0,
0xFF, 0xFF
])
);
}
#[test]
fn test_bit_vec_extend() {
let mut bit_vec = BitVec::from_bytes(&[0b10110110, 0b00000000, 0b11111111]);
let ext = BitVec::from_bytes(&[0b01001001, 0b10010010, 0b10111101]);
bit_vec.extend(ext.iter());
assert_eq!(
bit_vec,
BitVec::from_bytes(&[
0b10110110, 0b00000000, 0b11111111, 0b01001001, 0b10010010, 0b10111101
])
);
}
#[test]
fn test_bit_vec_append() {
// Append to BitVec that holds a multiple of U32_BITS bits
let mut a = BitVec::from_bytes(&[0b10100000, 0b00010010, 0b10010010, 0b00110011]);
let mut b = BitVec::new();
b.push(false);
b.push(true);
b.push(true);
a.append(&mut b);
assert_eq!(a.len(), 35);
assert_eq!(b.len(), 0);
assert!(b.capacity() >= 3);
assert!(a.eq_vec(&[
true, false, true, false, false, false, false, false, false, false, false, true, false,
false, true, false, true, false, false, true, false, false, true, false, false, false,
true, true, false, false, true, true, false, true, true
]));
// Append to arbitrary BitVec
let mut a = BitVec::new();
a.push(true);
a.push(false);
let mut b =
BitVec::from_bytes(&[0b10100000, 0b00010010, 0b10010010, 0b00110011, 0b10010101]);
a.append(&mut b);
assert_eq!(a.len(), 42);
assert_eq!(b.len(), 0);
assert!(b.capacity() >= 40);
assert!(a.eq_vec(&[
true, false, true, false, true, false, false, false, false, false, false, false, false,
true, false, false, true, false, true, false, false, true, false, false, true, false,
false, false, true, true, false, false, true, true, true, false, false, true, false,
true, false, true
]));
// Append to empty BitVec
let mut a = BitVec::new();
let mut b =
BitVec::from_bytes(&[0b10100000, 0b00010010, 0b10010010, 0b00110011, 0b10010101]);
a.append(&mut b);
assert_eq!(a.len(), 40);
assert_eq!(b.len(), 0);
assert!(b.capacity() >= 40);
assert!(a.eq_vec(&[
true, false, true, false, false, false, false, false, false, false, false, true, false,
false, true, false, true, false, false, true, false, false, true, false, false, false,
true, true, false, false, true, true, true, false, false, true, false, true, false,
true
]));
// Append empty BitVec
let mut a =
BitVec::from_bytes(&[0b10100000, 0b00010010, 0b10010010, 0b00110011, 0b10010101]);
let mut b = BitVec::new();
a.append(&mut b);
assert_eq!(a.len(), 40);
assert_eq!(b.len(), 0);
assert!(a.eq_vec(&[
true, false, true, false, false, false, false, false, false, false, false, true, false,
false, true, false, true, false, false, true, false, false, true, false, false, false,
true, true, false, false, true, true, true, false, false, true, false, true, false,
true
]));
}
#[test]
fn test_bit_vec_split_off() {
// Split at 0
let mut a = BitVec::new();
a.push(true);
a.push(false);
a.push(false);
a.push(true);
let b = a.split_off(0);
assert_eq!(a.len(), 0);
assert_eq!(b.len(), 4);
assert!(b.eq_vec(&[true, false, false, true]));
// Split at last bit
a.truncate(0);
a.push(true);
a.push(false);
a.push(false);
a.push(true);
let b = a.split_off(4);
assert_eq!(a.len(), 4);
assert_eq!(b.len(), 0);
assert!(a.eq_vec(&[true, false, false, true]));
// Split at block boundary
let mut a =
BitVec::from_bytes(&[0b10100000, 0b00010010, 0b10010010, 0b00110011, 0b11110011]);
let b = a.split_off(32);
assert_eq!(a.len(), 32);
assert_eq!(b.len(), 8);
assert!(a.eq_vec(&[
true, false, true, false, false, false, false, false, false, false, false, true, false,
false, true, false, true, false, false, true, false, false, true, false, false, false,
true, true, false, false, true, true
]));
assert!(b.eq_vec(&[true, true, true, true, false, false, true, true]));
// Don't split at block boundary
let mut a = BitVec::from_bytes(&[
0b10100000, 0b00010010, 0b10010010, 0b00110011, 0b01101011, 0b10101101,
]);
let b = a.split_off(13);
assert_eq!(a.len(), 13);
assert_eq!(b.len(), 35);
assert!(a.eq_vec(&[
true, false, true, false, false, false, false, false, false, false, false, true, false
]));
assert!(b.eq_vec(&[
false, true, false, true, false, false, true, false, false, true, false, false, false,
true, true, false, false, true, true, false, true, true, false, true, false, true,
true, true, false, true, false, true, true, false, true
]));
}
#[test]
fn test_into_iter() {
let bools = [true, false, true, true];
let bit_vec: BitVec = bools.iter().copied().collect();
let mut iter = bit_vec.into_iter();
assert_eq!(Some(true), iter.next());
assert_eq!(Some(false), iter.next());
assert_eq!(Some(true), iter.next());
assert_eq!(Some(true), iter.next());
assert_eq!(None, iter.next());
assert_eq!(None, iter.next());
let bit_vec: BitVec = bools.iter().copied().collect();
let mut iter = bit_vec.into_iter();
assert_eq!(Some(true), iter.next_back());
assert_eq!(Some(true), iter.next_back());
assert_eq!(Some(false), iter.next_back());
assert_eq!(Some(true), iter.next_back());
assert_eq!(None, iter.next_back());
assert_eq!(None, iter.next_back());
let bit_vec: BitVec = bools.iter().copied().collect();
let mut iter = bit_vec.into_iter();
assert_eq!(Some(true), iter.next_back());
assert_eq!(Some(true), iter.next());
assert_eq!(Some(false), iter.next());
assert_eq!(Some(true), iter.next_back());
assert_eq!(None, iter.next());
assert_eq!(None, iter.next_back());
}
#[test]
fn iter() {
let b = BitVec::with_capacity(10);
let _a: Iter = b.iter();
}
#[cfg(feature = "serde")]
#[test]
fn test_serialization() {
let bit_vec: BitVec = BitVec::new();
let serialized = serde_json::to_string(&bit_vec).unwrap();
let unserialized: BitVec = serde_json::from_str(&serialized).unwrap();
assert_eq!(bit_vec, unserialized);
let bools = vec![true, false, true, true];
let bit_vec: BitVec = bools.iter().map(|n| *n).collect();
let serialized = serde_json::to_string(&bit_vec).unwrap();
let unserialized = serde_json::from_str(&serialized).unwrap();
assert_eq!(bit_vec, unserialized);
}
#[cfg(feature = "miniserde")]
#[test]
fn test_miniserde_serialization() {
let bit_vec: BitVec = BitVec::new();
let serialized = miniserde::json::to_string(&bit_vec);
let unserialized: BitVec = miniserde::json::from_str(&serialized[..]).unwrap();
assert_eq!(bit_vec, unserialized);
let bools = vec![true, false, true, true];
let bit_vec: BitVec = bools.iter().map(|n| *n).collect();
let serialized = miniserde::json::to_string(&bit_vec);
let unserialized = miniserde::json::from_str(&serialized[..]).unwrap();
assert_eq!(bit_vec, unserialized);
}
#[cfg(feature = "nanoserde")]
#[test]
fn test_nanoserde_json_serialization() {
use nanoserde::{DeJson, SerJson};
let bit_vec: BitVec = BitVec::new();
let serialized = bit_vec.serialize_json();
let unserialized: BitVec = BitVec::deserialize_json(&serialized[..]).unwrap();
assert_eq!(bit_vec, unserialized);
let bools = vec![true, false, true, true];
let bit_vec: BitVec = bools.iter().map(|n| *n).collect();
let serialized = bit_vec.serialize_json();
let unserialized = BitVec::deserialize_json(&serialized[..]).unwrap();
assert_eq!(bit_vec, unserialized);
}
#[cfg(feature = "borsh")]
#[test]
fn test_borsh_serialization() {
let bit_vec: BitVec = BitVec::new();
let serialized = borsh::to_vec(&bit_vec).unwrap();
let unserialized: BitVec = borsh::from_slice(&serialized[..]).unwrap();
assert_eq!(bit_vec, unserialized);
let bools = vec![true, false, true, true];
let bit_vec: BitVec = bools.iter().map(|n| *n).collect();
let serialized = borsh::to_vec(&bit_vec).unwrap();
let unserialized = borsh::from_slice(&serialized[..]).unwrap();
assert_eq!(bit_vec, unserialized);
}
#[test]
fn test_bit_vec_unaligned_small_append() {
let mut a = BitVec::from_elem(8, false);
a.set(7, true);
let mut b = BitVec::from_elem(16, false);
b.set(14, true);
let mut c = BitVec::from_elem(8, false);
c.set(6, true);
c.set(7, true);
a.append(&mut b);
a.append(&mut c);
assert_eq!(&[1, 0, 2, 3][..], &*a.to_bytes());
}
#[test]
fn test_bit_vec_unaligned_large_append() {
let mut a = BitVec::from_elem(48, false);
a.set(47, true);
let mut b = BitVec::from_elem(48, false);
b.set(46, true);
let mut c = BitVec::from_elem(48, false);
c.set(46, true);
c.set(47, true);
a.append(&mut b);
a.append(&mut c);
assert_eq!(
&[
0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00,
0x00, 0x00, 0x00, 0x03
][..],
&*a.to_bytes()
);
}
#[test]
fn test_bit_vec_append_aligned_to_unaligned() {
let mut a = BitVec::from_elem(2, true);
let mut b = BitVec::from_elem(32, false);
let mut c = BitVec::from_elem(8, true);
a.append(&mut b);
a.append(&mut c);
assert_eq!(&[0xc0, 0x00, 0x00, 0x00, 0x3f, 0xc0][..], &*a.to_bytes());
}
#[test]
fn test_count_ones() {
for i in 0..1000 {
let mut t = BitVec::from_elem(i, true);
let mut f = BitVec::from_elem(i, false);
assert_eq!(i as u64, t.count_ones());
assert_eq!(0_u64, f.count_ones());
if i > 20 {
t.set(10, false);
t.set(i - 10, false);
assert_eq!(i - 2, t.count_ones() as usize);
f.set(10, true);
f.set(i - 10, true);
assert_eq!(2, f.count_ones());
}
}
}
#[test]
fn test_count_zeros() {
for i in 0..1000 {
let mut tbits = BitVec::from_elem(i, true);
let mut fbits = BitVec::from_elem(i, false);
assert_eq!(i as u64, fbits.count_zeros());
assert_eq!(0_u64, tbits.count_zeros());
if i > 20 {
fbits.set(10, true);
fbits.set(i - 10, true);
assert_eq!(i - 2, fbits.count_zeros() as usize);
tbits.set(10, false);
tbits.set(i - 10, false);
assert_eq!(2, tbits.count_zeros());
}
}
}
#[test]
fn test_get_mut() {
let mut a = BitVec::from_elem(3, false);
let mut a_bit_1 = a.get_mut(1).unwrap();
assert!(!*a_bit_1);
*a_bit_1 = true;
drop(a_bit_1);
assert!(a.eq_vec(&[false, true, false]));
}
#[test]
fn test_iter_mut() {
let mut a = BitVec::from_elem(8, false);
a.iter_mut().enumerate().for_each(|(index, mut bit)| {
*bit = index % 2 == 1;
});
assert!(a.eq_vec(&[false, true, false, true, false, true, false, true]));
}
#[test]
fn test_insert_at_zero() {
let mut v = BitVec::new();
v.insert(0, false);
v.insert(0, true);
v.insert(0, false);
v.insert(0, true);
v.insert(0, false);
v.insert(0, true);
assert_eq!(v.len(), 6);
assert_eq!(v.storage().len(), 1);
assert!(v.eq_vec(&[true, false, true, false, true, false]));
}
#[test]
fn test_insert_at_end() {
let mut v = BitVec::new();
v.insert(v.len(), true);
v.insert(v.len(), false);
v.insert(v.len(), true);
v.insert(v.len(), false);
v.insert(v.len(), true);
v.insert(v.len(), false);
assert_eq!(v.storage().len(), 1);
assert_eq!(v.len(), 6);
assert!(v.eq_vec(&[true, false, true, false, true, false]));
}
#[test]
fn test_insert_at_block_boundaries() {
let mut v = BitVec::from_elem(32, false);
assert_eq!(v.storage().len(), 1);
v.insert(31, true);
assert_eq!(v.len(), 33);
assert!(matches!(v.get(31), Some(true)));
assert!(v.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, true, false
]));
assert_eq!(v.storage().len(), 2);
}
#[test]
fn test_insert_at_block_boundaries_1() {
let mut v = BitVec::from_elem(64, false);
assert_eq!(v.storage().len(), 2);
v.insert(63, true);
assert_eq!(v.len(), 65);
assert!(matches!(v.get(63), Some(true)));
assert!(v.eq_vec(&[
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false, false, false,
false, false, false, true, false
]));
assert_eq!(v.storage().len(), 3);
}
}