Struct Bitvector 

pub struct Bitvector<const N: usize>(/* private fields */);

A homogenous collection of a fixed number of boolean values.

NOTE: a Bitvector of length 0 is illegal.

NOTE: once const_generics and const_evaluatable_checked features stabilize, this type can use something like bitvec::array::BitArray<T, {N / 8}> where T: BitRegister, [T; {N / 8}]: BitViewSized

Refer: https://stackoverflow.com/a/65462213

Implementations

impl<const N: usize> Bitvector<N>

pub fn get(&mut self, index: usize) -> Option<bool>

Return the bit at index. None if index is out-of-bounds.

pub fn set(&mut self, index: usize, value: bool) -> Option<bool>

Set the bit at index to value. Return the previous value or None if index is out-of-bounds.

Methods from Deref<Target = BitVec<u8, Lsb0>>

pub fn capacity(&self) -> usize

Gets the allocation capacity, measured in bits.

This counts how many total bits the bit-vector can store before it must perform a reällocation to acquire more memory.

If the capacity is not a multiple of 8, you should call .force_align().

Original

Vec::capacity

Examples

use bitvec::prelude::*;

let bv = bitvec![0, 1, 0, 0, 1];

pub fn reserve(&mut self, additional: usize)

Ensures that the bit-vector has allocation capacity for at least additional more bits to be appended to it.

For convenience, this method guarantees that the underlying memory for self[.. self.len() + additional] is initialized, and may be safely accessed directly without requiring use of .push() or .extend() to initialize it.

Newly-allocated memory is always initialized to zero. It is still dead until the bit-vector is grown (by .push(), .extend(), or .set_len()), but direct access will not trigger UB.

Original

Vec::reserve

Panics

This panics if the new capacity exceeds the bit-vector’s maximum.

Examples

use bitvec::prelude::*;

let mut bv: BitVec = BitVec::with_capacity(80);
assert!(bv.capacity() >= 80);
bv.reserve(800);
assert!(bv.capacity() >= 800);

pub fn reserve_exact(&mut self, additional: usize)

Ensures that the bit-vector has allocation capacity for at least additional more bits to be appended to it.

This differs from .reserve() by requesting that the allocator provide the minimum capacity necessary, rather than a potentially larger amount that the allocator may find more convenient.

Remember that this is a request: the allocator provides what it provides, and you cannot rely on the new capacity to be exactly minimal. You should still prefer .reserve(), especially if you expect to append to the bit-vector in the future.

Original

Vec::reserve_exact

Panics

This panics if the new capacity exceeds the bit-vector’s maximum.

Examples

use bitvec::prelude::*;

let mut bv: BitVec = BitVec::with_capacity(80);
assert!(bv.capacity() >= 80);
bv.reserve_exact(800);
assert!(bv.capacity() >= 800);

pub fn shrink_to_fit(&mut self)

Releases excess capacity back to the allocator.

Like .reserve_exact(), this is a request to the allocator, not a command. The allocator may reclaim excess memory or may not.

Original

Vec::shrink_to_fit

Examples

use bitvec::prelude::*;

let mut bv: BitVec = BitVec::with_capacity(1000);
bv.push(true);
bv.shrink_to_fit();

pub fn truncate(&mut self, new_len: usize)

Shortens the bit-vector, keeping the first new_len bits and discarding the rest.

If len is greater than the bit-vector’s current length, this has no effect.

The .drain() method can emulate .truncate(), except that it yields the excess bits rather than discarding them.

Note that this has no effect on the allocated capacity of the bit-vector, nor does it erase truncated memory. Bits in the allocated memory that are outside of the .as_bitslice() view are always considered to have initialized, but unspecified, values, and you cannot rely on them to be zero.

Original

Vec::truncate

Examples

Truncating a five-bit vector to two bits:

use bitvec::prelude::*;

let mut bv = bitvec![0, 1, 0, 0, 1];
bv.truncate(2);
assert_eq!(bv.len(), 2);
assert!(bv.as_raw_slice()[0].count_ones() >= 2);

No truncation occurs when len is greater than the bit-vector’s current length:

pub fn as_slice(&self) -> &BitSlice<T, O>

👎Deprecated: use .as_bitslice() instead

pub fn as_mut_slice(&mut self) -> &mut BitSlice<T, O>

👎Deprecated: use .as_mut_bitslice() instead

pub fn as_ptr(&self) -> BitPtr<Const, T, O>

👎Deprecated: use .as_bitptr() instead

pub fn as_mut_ptr(&mut self) -> BitPtr<Mut, T, O>

👎Deprecated: use .as_mut_bitptr() instead

pub unsafe fn set_len(&mut self, new_len: usize)

Resizes a bit-vector to a new length.

Original

Vec::set_len

Safety

NOT ALL MEMORY IN THE ALLOCATION IS INITIALIZED!

Memory in a bit-vector’s allocation is only initialized when the bit-vector grows into it normally (through .push() or one of the various .extend*() methods). Setting the length to a value beyond what was previously initialized, but still within the allocation, is undefined behavior.

The caller is responsible for ensuring that all memory up to (but not including) the new length has already been initialized.

Panics

This panics if new_len exceeds the capacity as reported by .capacity().

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1, 0, 0, 1];
unsafe {
  // The default storage type, `usize`, is at least 32 bits.
  bv.set_len(32);
}
assert_eq!(bv, bits![
  0, 1, 0, 0, 1, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,
]);
//  `BitVec` guarantees that newly-initialized memory is zeroed.

pub fn swap_remove(&mut self, index: usize) -> bool

Takes a bit out of the bit-vector.

The empty slot is filled with the last bit in the bit-vector, rather than shunting index + 1 .. self.len() down by one.

Original

Vec::swap_remove

Panics

This panics if index is out of bounds (self.len() or greater).

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1, 0, 0, 1];
assert!(!bv.swap_remove(2));
assert_eq!(bv, bits![0, 1, 1, 0]);

pub fn insert(&mut self, index: usize, value: bool)

Inserts a bit at a given position, shifting all bits after it one spot to the right.

index may be any value up to and including self.len(). If it is self.len(), it behaves equivalently to .push().

Original

Vec::insert

Panics

This panics if index is out of bounds (including self.len()).

pub fn remove(&mut self, index: usize) -> bool

Removes a bit at a given position, shifting all bits after it one spot to the left.

index may be any value up to, but not including, self.len().

Original

Vec::remove

Panics

This panics if index is out of bounds (excluding self.len()).

pub fn retain<F>(&mut self, func: F)

where F: FnMut(usize, &bool) -> bool,

Retains only the bits that the predicate allows.

Bits are deleted from the vector when the predicate function returns false. This function is linear in self.len().

Original

Vec::retain

API Differences

The predicate receives both the index of the bit as well as its value, in order to allow the predicate to have more than one bit of keep/discard information.

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1, 0, 0, 1];
bv.retain(|idx, _| idx % 2 == 0);
assert_eq!(bv, bits![0,    0,    1]);

pub fn push(&mut self, value: bool)

Appends a single bit to the vector.

Original

Vec::push

Panics

This panics if the push would cause the bit-vector to exceed its maximum capacity.

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 0];
bv.push(true);
assert_eq!(bv.as_bitslice(), bits![0, 0, 1]);

pub fn pop(&mut self) -> Option<bool>

Attempts to remove the trailing bit from the bit-vector.

This returns None if the bit-vector is empty.

Original

Vec::pop

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1];
assert!(bv.pop().unwrap());
assert!(!bv.pop().unwrap());
assert!(bv.pop().is_none());

pub fn append<T2, O2>(&mut self, other: &mut BitVec<T2, O2>)

where T2: BitStore, O2: BitOrder,

Moves all the bits out of other into the back of self.

The other bit-vector is emptied after this occurs.

Original

Vec::append

API Differences

This permits other to have different type parameters than self, and does not require that it be literally Self.

Panics

This panics if self.len() + other.len() exceeds the maximum capacity of a bit-vector.

Examples

use bitvec::prelude::*;

let mut bv1 = bitvec![u16, Msb0; 0; 10];
let mut bv2 = bitvec![u32, Lsb0; 1; 10];

bv1.append(&mut bv2);

assert_eq!(bv1.count_ones(), 10);
assert_eq!(bv1.count_zeros(), 10);
assert!(bv2.is_empty());

pub fn drain<R>(&mut self, range: R) -> Drain<'_, T, O>

where R: RangeBounds<usize>,

Iterates over a portion of the bit-vector, removing all yielded bits from it.

When the iterator drops, all bits in its coverage are removed from self, even if the iterator did not yield them. If the iterator is leaked or otherwise forgotten, and its destructor never runs, then the amount of un-yielded bits removed from the bit-vector is not specified.

Original

Vec::drain

Panics

This panics if range departs 0 .. self.len().

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1, 0, 0, 1];
let bv2 = bv.drain(1 ..= 3).collect::<BitVec>();
assert_eq!(bv, bits![0,          1]);
assert_eq!(bv2, bits![1, 0, 0]);

// A full range clears the bit-vector.
bv.drain(..);
assert!(bv.is_empty());

pub fn clear(&mut self)

Empties the bit-vector.

This does not affect the allocated capacity.

Original

Vec::clear

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1, 0, 0, 1];
bv.clear();
assert!(bv.is_empty());

pub fn len(&self) -> usize

Gets the length of the bit-vector.

This is equivalent to BitSlice::len; it is provided as an inherent method here rather than relying on Deref forwarding so that you can write BitVec::len as a named function item.

Original

Vec::len

pub fn is_empty(&self) -> bool

Tests if the bit-vector is empty.

This is equivalent to BitSlice::is_empty; it is provided as an inherent method here rather than relying on Deref forwarding so that you can write BitVec::is_empty as a named function item.

Original

Vec::is_empty

pub fn split_off(&mut self, at: usize) -> BitVec<T, O>

Splits the bit-vector in half at an index, moving self[at ..] out into a new bit-vector.

Original

Vec::split_off

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1, 0, 0, 1];
let bv2 = bv.split_off(2);
assert_eq!((&*bv, &*bv2), (bits![0, 1], bits![0, 0, 1]));

pub fn resize_with<F>(&mut self, new_len: usize, func: F)

where F: FnMut(usize) -> bool,

Resizes the bit-vector to a new length, using a function to produce each inserted bit.

If new_len is less than self.len(), this is a truncate operation; if it is greater, then self is extended by repeatedly pushing func().

Original

Vec::resize_with

API Differences

The generator function receives the index into which its bit will be placed.

Examples

use bitvec::prelude::*;

let mut bv = bitvec![1; 2];
bv.resize_with(5, |idx| idx % 2 == 1);
assert_eq!(bv, bits![1, 1, 0, 1, 0]);

pub fn resize(&mut self, new_len: usize, value: bool)

Resizes the bit-vector to a new length. New bits are initialized to value.

Original

Vec::resize

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0; 2];
bv.resize(5, true);
assert_eq!(bv, bits![0, 0, 1, 1, 1]);

pub fn extend_from_slice<T2, O2>(&mut self, other: &BitSlice<T2, O2>)

where T2: BitStore, O2: BitOrder,

👎Deprecated: use .extend_from_bitslice() or .extend_from_raw_slice() instead

pub fn extend_from_within<R>(&mut self, src: R)

where R: RangeExt<usize>,

Extends self by copying an internal range of its bit-slice as the region to append.

Original

Vec::extend_from_within

Panics

This panics if src is not within 0 .. self.len().

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1, 0, 0, 1];
bv.extend_from_within(1 .. 4);
assert_eq!(bv, bits![0, 1, 0, 0, 1, 1, 0, 0]);

pub fn splice<R, I>( &mut self, range: R, replace_with: I, ) -> Splice<'_, T, O, <I as IntoIterator>::IntoIter>

where R: RangeBounds<usize>, I: IntoIterator<Item = bool>,

Modifies self.drain() so that the removed bit-slice is instead replaced with the contents of another bit-stream.

As with .drain(), the specified range is always removed from the bit-vector even if the splicer is not fully consumed, and the splicer does not specify how many bits are removed if it leaks.

The replacement source is only consumed when the splicer drops; however, it may be pulled before then. The replacement source cannot assume that there will be a delay between creation of the splicer and when it must begin producing bits.

This copies the Vec::splice implementation; see its documentation for more details about how the replacement should act.

Original

Vec::splice

Panics

This panics if range departs 0 .. self.len().

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1, 1];
//                   a  b  c
let mut yank = bv.splice(
  .. 2,
  bits![static 1, 1, 0].iter().by_vals(),
//             d  e  f
);

assert!(!yank.next().unwrap()); // a
assert!(yank.next().unwrap()); // b
drop(yank);
assert_eq!(bv, bits![1, 1, 0, 1]);
//                   d  e  f  c

pub const EMPTY: BitVec<T, O>

pub fn extend_from_bitslice<T2, O2>(&mut self, other: &BitSlice<T2, O2>)

where T2: BitStore, O2: BitOrder,

Appends the contents of a bit-slice to a bit-vector.

This can extend from a bit-slice of any type parameters; it is not restricted to using the same parameters as self. However, when the type parameters do match, it is possible for this to use a batch-copy optimization to go faster than the individual-bit crawl that is necessary when they differ.

Until Rust provides extensive support for specialization in trait implementations, you should use this method whenever you are extending from a BitSlice proper, and only use the general .extend() implementation if you are required to use a generic bool source.

Original

Vec::extend_from_slice

Examples

use bitvec::prelude::*;

let mut bv = bitvec![0, 1];
bv.extend_from_bitslice(bits![0, 1, 0, 0, 1]);
assert_eq!(bv, bits![0, 1, 0, 1, 0, 0, 1]);

pub fn extend_from_raw_slice(&mut self, slice: &[T])

Appends a slice of T elements to a bit-vector.

The slice is viewed as a BitSlice<T, O>, then appended directly to the bit-vector.

Original

Vec::extend_from_slice

pub fn as_bitslice(&self) -> &BitSlice<T, O>

Explicitly views the bit-vector as a bit-slice.

pub fn as_mut_bitslice(&mut self) -> &mut BitSlice<T, O>

Explicitly views the bit-vector as a mutable bit-slice.

pub fn as_raw_slice(&self) -> &[T]

Views the bit-vector as a slice of its underlying memory elements.

pub fn as_raw_mut_slice(&mut self) -> &mut [T]

Views the bit-vector as a mutable slice of its underlying memory elements.

pub fn as_bitptr(&self) -> BitPtr<Const, T, O>

Creates an unsafe shared bit-pointer to the start of the buffer.

Original

Vec::as_ptr

Safety

You must initialize the contents of the underlying buffer before accessing memory through this pointer. See the BitPtr documentation for more details.

pub fn as_mut_bitptr(&mut self) -> BitPtr<Mut, T, O>

Creates an unsafe writable bit-pointer to the start of the buffer.

Original

Vec::as_mut_ptr

Safety

You must initialize the contents of the underlying buffer before accessing memory through this pointer. See the BitPtr documentation for more details.

pub fn set_elements(&mut self, element: <T as BitStore>::Mem)

Overwrites each element (visible in .as_raw_mut_slice()) with a new bit-pattern.

This unconditionally writes element into each element in the backing slice, without altering the bit-vector’s length or capacity.

This guarantees that dead bits visible in .as_raw_slice() but not .as_bitslice() are initialized according to the bit-pattern of element. The elements not visible in the raw slice, but present in the allocation, do not specify a value. You may not rely on them being zeroed or being set to the element bit-pattern.

Parameters

• &mut self
• element: The bit-pattern with which each live element in the backing store is initialized.

Examples

use bitvec::prelude::*;

let mut bv = bitvec![u8, Msb0; 0; 20];
assert_eq!(bv.as_raw_slice(), [0; 3]);
bv.set_elements(0xA5);
assert_eq!(bv.as_raw_slice(), [0xA5; 3]);

pub fn set_uninitialized(&mut self, value: bool)

Sets the uninitialized bits of a bit-vector to a known value.

This method modifies all bits that are observable in .as_raw_slice() but not observable in .as_bitslice() to a known value. Memory beyond the raw-slice view, but still within the allocation, is considered fully dead and will never be seen.

This can be used to zero the unused memory so that when viewed as a raw slice, unused bits have a consistent and predictable value.

Examples

use bitvec::prelude::*;

let mut bv = 0b1101_1100u8.view_bits::<Lsb0>().to_bitvec();
assert_eq!(bv.as_raw_slice()[0], 0b1101_1100u8);

bv.truncate(4);
assert_eq!(bv.count_ones(), 2);
assert_eq!(bv.as_raw_slice()[0], 0b1101_1100u8);

bv.set_uninitialized(false);
assert_eq!(bv.as_raw_slice()[0], 0b0000_1100u8);

bv.set_uninitialized(true);
assert_eq!(bv.as_raw_slice()[0], 0b1111_1100u8);

pub fn force_align(&mut self)

Ensures that the live region of the bit-vector’s contents begin at the front edge of the buffer.

BitVec has performance optimizations where it moves its view of its buffer contents in order to avoid needless moves of its data within the buffer. This can lead to unexpected contents of the raw memory values, so this method ensures that the semantic contents of the bit-vector match its in-memory storage.

Examples

use bitvec::prelude::*;

let data = 0b00_1111_00u8;
let bits = data.view_bits::<Msb0>();

let mut bv = bits[2 .. 6].to_bitvec();
assert_eq!(bv, bits![1; 4]);
assert_eq!(bv.as_raw_slice()[0], data);

bv.force_align();
assert_eq!(bv, bits![1; 4]);
// BitVec does not specify the value of dead bits in its buffer.
assert_eq!(bv.as_raw_slice()[0] & 0xF0, 0xF0);

Methods from Deref<Target = BitSlice<T, O>>

pub fn len(&self) -> usize

Gets the number of bits in the bit-slice.

Original

slice::len

Examples

use bitvec::prelude::*;

assert_eq!(bits![].len(), 0);
assert_eq!(bits![0; 10].len(), 10);

pub fn is_empty(&self) -> bool

Tests if the bit-slice is empty (length zero).

Original

slice::is_empty

Examples

use bitvec::prelude::*;

assert!(bits![].is_empty());
assert!(!bits![0; 10].is_empty());

pub fn first(&self) -> Option<BitRef<'_, Const, T, O>>

Gets a reference to the first bit of the bit-slice, or None if it is empty.

Original

slice::first

API Differences

bitvec uses a custom structure for both read-only and mutable references to bool.

Examples

use bitvec::prelude::*;

let bits = bits![1, 0, 0];
assert_eq!(bits.first().as_deref(), Some(&true));

assert!(bits![].first().is_none());

pub fn first_mut(&mut self) -> Option<BitRef<'_, Mut, T, O>>

Gets a mutable reference to the first bit of the bit-slice, or None if it is empty.

Original

slice::first_mut

API Differences

bitvec uses a custom structure for both read-only and mutable references to bool. This must be bound as mut in order to write through it.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0; 3];
if let Some(mut first) = bits.first_mut() {
  *first = true;
}
assert_eq!(bits, bits![1, 0, 0]);

assert!(bits![mut].first_mut().is_none());

pub fn split_first(&self) -> Option<(BitRef<'_, Const, T, O>, &BitSlice<T, O>)>

Splits the bit-slice into a reference to its first bit, and the rest of the bit-slice. Returns None when empty.

Original

slice::split_first

API Differences

bitvec uses a custom structure for both read-only and mutable references to bool.

Examples

use bitvec::prelude::*;

let bits = bits![1, 0, 0];
let (first, rest) = bits.split_first().unwrap();
assert_eq!(first, &true);
assert_eq!(rest, bits![0; 2]);

pub fn split_first_mut( &mut self, ) -> Option<(BitRef<'_, Mut, <T as BitStore>::Alias, O>, &mut BitSlice<<T as BitStore>::Alias, O>)>

Splits the bit-slice into mutable references of its first bit, and the rest of the bit-slice. Returns None when empty.

Original

slice::split_first_mut

API Differences

bitvec uses a custom structure for both read-only and mutable references to bool. This must be bound as mut in order to write through it.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0; 3];
if let Some((mut first, rest)) = bits.split_first_mut() {
  *first = true;
  assert_eq!(rest, bits![0; 2]);
}
assert_eq!(bits, bits![1, 0, 0]);

pub fn split_last(&self) -> Option<(BitRef<'_, Const, T, O>, &BitSlice<T, O>)>

Splits the bit-slice into a reference to its last bit, and the rest of the bit-slice. Returns None when empty.

Original

slice::split_last

API Differences

bitvec uses a custom structure for both read-only and mutable references to bool.

Examples

use bitvec::prelude::*;

let bits = bits![0, 0, 1];
let (last, rest) = bits.split_last().unwrap();
assert_eq!(last, &true);
assert_eq!(rest, bits![0; 2]);

pub fn split_last_mut( &mut self, ) -> Option<(BitRef<'_, Mut, <T as BitStore>::Alias, O>, &mut BitSlice<<T as BitStore>::Alias, O>)>

Splits the bit-slice into mutable references to its last bit, and the rest of the bit-slice. Returns None when empty.

Original

slice::split_last_mut

API Differences

bitvec uses a custom structure for both read-only and mutable references to bool. This must be bound as mut in order to write through it.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0; 3];
if let Some((mut last, rest)) = bits.split_last_mut() {
  *last = true;
  assert_eq!(rest, bits![0; 2]);
}
assert_eq!(bits, bits![0, 0, 1]);

pub fn last(&self) -> Option<BitRef<'_, Const, T, O>>

Gets a reference to the last bit of the bit-slice, or None if it is empty.

Original

slice::last

API Differences

bitvec uses a custom structure for both read-only and mutable references to bool.

Examples

use bitvec::prelude::*;

let bits = bits![0, 0, 1];
assert_eq!(bits.last().as_deref(), Some(&true));

assert!(bits![].last().is_none());

pub fn last_mut(&mut self) -> Option<BitRef<'_, Mut, T, O>>

Gets a mutable reference to the last bit of the bit-slice, or None if it is empty.

Original

slice::last_mut

API Differences

bitvec uses a custom structure for both read-only and mutable references to bool. This must be bound as mut in order to write through it.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0; 3];
if let Some(mut last) = bits.last_mut() {
  *last = true;
}
assert_eq!(bits, bits![0, 0, 1]);

assert!(bits![mut].last_mut().is_none());

pub fn get<'a, I>( &'a self, index: I, ) -> Option<<I as BitSliceIndex<'a, T, O>>::Immut>

where I: BitSliceIndex<'a, T, O>,

Gets a reference to a single bit or a subsection of the bit-slice, depending on the type of index.

• If given a usize, this produces a reference structure to the bool at the position.
• If given any form of range, this produces a smaller bit-slice.

This returns None if the index departs the bounds of self.

Original

slice::get

API Differences

BitSliceIndex uses discrete types for immutable and mutable references, rather than a single referent type.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0];
assert_eq!(bits.get(1).as_deref(), Some(&true));
assert_eq!(bits.get(0 .. 2), Some(bits![0, 1]));
assert!(bits.get(3).is_none());
assert!(bits.get(0 .. 4).is_none());

pub fn get_mut<'a, I>( &'a mut self, index: I, ) -> Option<<I as BitSliceIndex<'a, T, O>>::Mut>

where I: BitSliceIndex<'a, T, O>,

Gets a mutable reference to a single bit or a subsection of the bit-slice, depending on the type of index.

• If given a usize, this produces a reference structure to the bool at the position.
• If given any form of range, this produces a smaller bit-slice.

This returns None if the index departs the bounds of self.

Original

slice::get_mut

API Differences

BitSliceIndex uses discrete types for immutable and mutable references, rather than a single referent type.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0; 3];

*bits.get_mut(0).unwrap() = true;
bits.get_mut(1 ..).unwrap().fill(true);
assert_eq!(bits, bits![1; 3]);

pub unsafe fn get_unchecked<'a, I>( &'a self, index: I, ) -> <I as BitSliceIndex<'a, T, O>>::Immut

where I: BitSliceIndex<'a, T, O>,

Gets a reference to a single bit or to a subsection of the bit-slice, without bounds checking.

This has the same arguments and behavior as .get(), except that it does not check that index is in bounds.

Original

slice::get_unchecked

Safety

You must ensure that index is within bounds (within the range 0 .. self.len()), or this method will introduce memory safety and/or undefined behavior.

It is library-level undefined behavior to index beyond the length of any bit-slice, even if you know that the offset remains within an allocation as measured by Rust or LLVM.

Examples

use bitvec::prelude::*;

let data = 0b0001_0010u8;
let bits = &data.view_bits::<Lsb0>()[.. 3];

unsafe {
  assert!(bits.get_unchecked(1));
  assert!(bits.get_unchecked(4));
}

pub unsafe fn get_unchecked_mut<'a, I>( &'a mut self, index: I, ) -> <I as BitSliceIndex<'a, T, O>>::Mut

where I: BitSliceIndex<'a, T, O>,

Gets a mutable reference to a single bit or a subsection of the bit-slice, depending on the type of index.

This has the same arguments and behavior as .get_mut(), except that it does not check that index is in bounds.

Original

slice::get_unchecked_mut

Safety

You must ensure that index is within bounds (within the range 0 .. self.len()), or this method will introduce memory safety and/or undefined behavior.

It is library-level undefined behavior to index beyond the length of any bit-slice, even if you know that the offset remains within an allocation as measured by Rust or LLVM.

Examples

use bitvec::prelude::*;

let mut data = 0u8;
let bits = &mut data.view_bits_mut::<Lsb0>()[.. 3];

unsafe {
  bits.get_unchecked_mut(1).commit(true);
  bits.get_unchecked_mut(4 .. 6).fill(true);
}
assert_eq!(data, 0b0011_0010);

pub fn as_ptr(&self) -> BitPtr<Const, T, O>

👎Deprecated: use .as_bitptr() instead

pub fn as_mut_ptr(&mut self) -> BitPtr<Mut, T, O>

👎Deprecated: use .as_mut_bitptr() instead

pub fn as_ptr_range(&self) -> Range<BitPtr<Const, T, O>>

Produces a range of bit-pointers to each bit in the bit-slice.

This is a standard-library range, which has no real functionality for pointer types. You should prefer .as_bitptr_range() instead, as it produces a custom structure that provides expected ranging functionality.

Original

slice::as_ptr_range

pub fn as_mut_ptr_range(&mut self) -> Range<BitPtr<Mut, T, O>>

Produces a range of mutable bit-pointers to each bit in the bit-slice.

This is a standard-library range, which has no real functionality for pointer types. You should prefer .as_mut_bitptr_range() instead, as it produces a custom structure that provides expected ranging functionality.

Original

slice::as_mut_ptr_range

pub fn swap(&mut self, a: usize, b: usize)

Exchanges the bit values at two indices.

Original

slice::swap

Panics

This panics if either a or b are out of bounds.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 1];
bits.swap(0, 1);
assert_eq!(bits, bits![1, 0]);

pub fn reverse(&mut self)

Reverses the order of bits in a bit-slice.

Original

slice::reverse

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 0, 1, 0, 1, 1, 0, 0, 1];
bits.reverse();
assert_eq!(bits, bits![1, 0, 0, 1, 1, 0, 1, 0, 0]);

pub fn iter(&self) -> Iter<'_, T, O>

Produces an iterator over each bit in the bit-slice.

Original

slice::iter

API Differences

This iterator yields proxy-reference structures, not &bool. It can be adapted to yield &bool with the .by_refs() method, or bool with .by_vals().

This iterator, and its adapters, are fast. Do not try to be more clever than them by abusing .as_bitptr_range().

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 1];
let mut iter = bits.iter();

assert!(!iter.next().unwrap());
assert!( iter.next().unwrap());
assert!( iter.next_back().unwrap());
assert!(!iter.next_back().unwrap());
assert!( iter.next().is_none());

pub fn iter_mut(&mut self) -> IterMut<'_, T, O>

Produces a mutable iterator over each bit in the bit-slice.

Original

slice::iter_mut

API Differences

This iterator yields proxy-reference structures, not &mut bool. In addition, it marks each proxy as alias-tainted.

If you are using this in an ordinary loop and not keeping multiple yielded proxy-references alive at the same scope, you may use the .remove_alias() adapter to undo the alias marking.

This iterator is fast. Do not try to be more clever than it by abusing .as_mut_bitptr_range().

Examples

use bitvec::prelude::*;

let bits = bits![mut 0; 4];
let mut iter = bits.iter_mut();

iter.nth(1).unwrap().commit(true); // index 1
iter.next_back().unwrap().commit(true); // index 3

assert!(iter.next().is_some()); // index 2
assert!(iter.next().is_none()); // complete
assert_eq!(bits, bits![0, 1, 0, 1]);

pub fn windows(&self, size: usize) -> Windows<'_, T, O>

Iterates over consecutive windowing subslices in a bit-slice.

Windows are overlapping views of the bit-slice. Each window advances one bit from the previous, so in a bit-slice [A, B, C, D, E], calling .windows(3) will yield [A, B, C], [B, C, D], and [C, D, E].

Original

slice::windows

Panics

This panics if size is 0.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1];
let mut iter = bits.windows(3);

assert_eq!(iter.next(), Some(bits![0, 1, 0]));
assert_eq!(iter.next(), Some(bits![1, 0, 0]));
assert_eq!(iter.next(), Some(bits![0, 0, 1]));
assert!(iter.next().is_none());

pub fn chunks(&self, chunk_size: usize) -> Chunks<'_, T, O>

Iterates over non-overlapping subslices of a bit-slice.

Unlike .windows(), the subslices this yields do not overlap with each other. If self.len() is not an even multiple of chunk_size, then the last chunk yielded will be shorter.

Original

slice::chunks

Sibling Methods

• .chunks_mut() has the same division logic, but each yielded bit-slice is mutable.
• .chunks_exact() does not yield the final chunk if it is shorter than chunk_size.
• .rchunks() iterates from the back of the bit-slice to the front, with the final, possibly-shorter, segment at the front edge.

Panics

This panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1];
let mut iter = bits.chunks(2);

assert_eq!(iter.next(), Some(bits![0, 1]));
assert_eq!(iter.next(), Some(bits![0, 0]));
assert_eq!(iter.next(), Some(bits![1]));
assert!(iter.next().is_none());

pub fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<'_, T, O>

Iterates over non-overlapping mutable subslices of a bit-slice.

Iterators do not require that each yielded item is destroyed before the next is produced. This means that each bit-slice yielded must be marked as aliased. If you are using this in a loop that does not collect multiple yielded subslices for the same scope, then you can remove the alias marking by calling the (unsafe) method .remove_alias() on the iterator.

Original

slice::chunks_mut

Sibling Methods

• .chunks() has the same division logic, but each yielded bit-slice is immutable.
• .chunks_exact_mut() does not yield the final chunk if it is shorter than chunk_size.
• .rchunks_mut() iterates from the back of the bit-slice to the front, with the final, possibly-shorter, segment at the front edge.

Panics

This panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let bits = bits![mut u8, Msb0; 0; 5];

for (idx, chunk) in unsafe {
  bits.chunks_mut(2).remove_alias()
}.enumerate() {
  chunk.store(idx + 1);
}
assert_eq!(bits, bits![0, 1, 1, 0, 1]);
//                     ^^^^  ^^^^  ^

pub fn chunks_exact(&self, chunk_size: usize) -> ChunksExact<'_, T, O>

Iterates over non-overlapping subslices of a bit-slice.

If self.len() is not an even multiple of chunk_size, then the last few bits are not yielded by the iterator at all. They can be accessed with the .remainder() method if the iterator is bound to a name.

Original

slice::chunks_exact

Sibling Methods

• .chunks() yields any leftover bits at the end as a shorter chunk during iteration.
• .chunks_exact_mut() has the same division logic, but each yielded bit-slice is mutable.
• .rchunks_exact() iterates from the back of the bit-slice to the front, with the unyielded remainder segment at the front edge.

Panics

This panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1];
let mut iter = bits.chunks_exact(2);

assert_eq!(iter.next(), Some(bits![0, 1]));
assert_eq!(iter.next(), Some(bits![0, 0]));
assert!(iter.next().is_none());
assert_eq!(iter.remainder(), bits![1]);

pub fn chunks_exact_mut( &mut self, chunk_size: usize, ) -> ChunksExactMut<'_, T, O>

Iterates over non-overlapping mutable subslices of a bit-slice.

If self.len() is not an even multiple of chunk_size, then the last few bits are not yielded by the iterator at all. They can be accessed with the .into_remainder() method if the iterator is bound to a name.

Iterators do not require that each yielded item is destroyed before the next is produced. This means that each bit-slice yielded must be marked as aliased. If you are using this in a loop that does not collect multiple yielded subslices for the same scope, then you can remove the alias marking by calling the (unsafe) method .remove_alias() on the iterator.

Original

slice::chunks_exact_mut

Sibling Methods

• .chunks_mut() yields any leftover bits at the end as a shorter chunk during iteration.
• .chunks_exact() has the same division logic, but each yielded bit-slice is immutable.
• .rchunks_exact_mut() iterates from the back of the bit-slice forwards, with the unyielded remainder segment at the front edge.

Panics

This panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let bits = bits![mut u8, Msb0; 0; 5];
let mut iter = bits.chunks_exact_mut(2);

for (idx, chunk) in iter.by_ref().enumerate() {
  chunk.store(idx + 1);
}
iter.into_remainder().store(1u8);

assert_eq!(bits, bits![0, 1, 1, 0, 1]);
//                       remainder ^

pub fn rchunks(&self, chunk_size: usize) -> RChunks<'_, T, O>

Iterates over non-overlapping subslices of a bit-slice, from the back edge.

Unlike .chunks(), this aligns its chunks to the back edge of self. If self.len() is not an even multiple of chunk_size, then the leftover partial chunk is self[0 .. len % chunk_size].

Original

slice::rchunks

Sibling Methods

• .rchunks_mut() has the same division logic, but each yielded bit-slice is mutable.
• .rchunks_exact() does not yield the final chunk if it is shorter than chunk_size.
• .chunks() iterates from the front of the bit-slice to the back, with the final, possibly-shorter, segment at the back edge.

Panics

This panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1];
let mut iter = bits.rchunks(2);

assert_eq!(iter.next(), Some(bits![0, 1]));
assert_eq!(iter.next(), Some(bits![1, 0]));
assert_eq!(iter.next(), Some(bits![0]));
assert!(iter.next().is_none());

pub fn rchunks_mut(&mut self, chunk_size: usize) -> RChunksMut<'_, T, O>

Iterates over non-overlapping mutable subslices of a bit-slice, from the back edge.

Unlike .chunks_mut(), this aligns its chunks to the back edge of self. If self.len() is not an even multiple of chunk_size, then the leftover partial chunk is self[0 .. len % chunk_size].

Iterators do not require that each yielded item is destroyed before the next is produced. This means that each bit-slice yielded must be marked as aliased. If you are using this in a loop that does not collect multiple yielded values for the same scope, then you can remove the alias marking by calling the (unsafe) method .remove_alias() on the iterator.

Original

slice::rchunks_mut

Sibling Methods

• .rchunks() has the same division logic, but each yielded bit-slice is immutable.
• .rchunks_exact_mut() does not yield the final chunk if it is shorter than chunk_size.
• .chunks_mut() iterates from the front of the bit-slice to the back, with the final, possibly-shorter, segment at the back edge.

Examples

use bitvec::prelude::*;

let bits = bits![mut u8, Msb0; 0; 5];
for (idx, chunk) in unsafe {
  bits.rchunks_mut(2).remove_alias()
}.enumerate() {
  chunk.store(idx + 1);
}
assert_eq!(bits, bits![1, 1, 0, 0, 1]);
//           remainder ^  ^^^^  ^^^^

pub fn rchunks_exact(&self, chunk_size: usize) -> RChunksExact<'_, T, O>

Iterates over non-overlapping subslices of a bit-slice, from the back edge.

If self.len() is not an even multiple of chunk_size, then the first few bits are not yielded by the iterator at all. They can be accessed with the .remainder() method if the iterator is bound to a name.

Original

slice::rchunks_exact

Sibling Methods

• .rchunks() yields any leftover bits at the front as a shorter chunk during iteration.
• .rchunks_exact_mut() has the same division logic, but each yielded bit-slice is mutable.
• .chunks_exact() iterates from the front of the bit-slice to the back, with the unyielded remainder segment at the back edge.

Panics

This panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1];
let mut iter = bits.rchunks_exact(2);

assert_eq!(iter.next(), Some(bits![0, 1]));
assert_eq!(iter.next(), Some(bits![1, 0]));
assert!(iter.next().is_none());
assert_eq!(iter.remainder(), bits![0]);

pub fn rchunks_exact_mut( &mut self, chunk_size: usize, ) -> RChunksExactMut<'_, T, O>

Iterates over non-overlapping mutable subslices of a bit-slice, from the back edge.

If self.len() is not an even multiple of chunk_size, then the first few bits are not yielded by the iterator at all. They can be accessed with the .into_remainder() method if the iterator is bound to a name.

Iterators do not require that each yielded item is destroyed before the next is produced. This means that each bit-slice yielded must be marked as aliased. If you are using this in a loop that does not collect multiple yielded subslices for the same scope, then you can remove the alias marking by calling the (unsafe) method .remove_alias() on the iterator.

Sibling Methods

• .rchunks_mut() yields any leftover bits at the front as a shorter chunk during iteration.
• .rchunks_exact() has the same division logic, but each yielded bit-slice is immutable.
• .chunks_exact_mut() iterates from the front of the bit-slice backwards, with the unyielded remainder segment at the back edge.

Panics

This panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let bits = bits![mut u8, Msb0; 0; 5];
let mut iter = bits.rchunks_exact_mut(2);

for (idx, chunk) in iter.by_ref().enumerate() {
  chunk.store(idx + 1);
}
iter.into_remainder().store(1u8);

assert_eq!(bits, bits![1, 1, 0, 0, 1]);
//           remainder ^

pub fn split_at(&self, mid: usize) -> (&BitSlice<T, O>, &BitSlice<T, O>)

Splits a bit-slice in two parts at an index.

The returned bit-slices are self[.. mid] and self[mid ..]. mid is included in the right bit-slice, not the left.

If mid is 0 then the left bit-slice is empty; if it is self.len() then the right bit-slice is empty.

This method guarantees that even when either partition is empty, the encoded bit-pointer values of the bit-slice references is &self[0] and &self[mid].

Original

slice::split_at

Panics

This panics if mid is greater than self.len(). It is allowed to be equal to the length, in which case the right bit-slice is simply empty.

Examples

use bitvec::prelude::*;

let bits = bits![0, 0, 0, 1, 1, 1];
let base = bits.as_bitptr();

let (a, b) = bits.split_at(0);
assert_eq!(unsafe { a.as_bitptr().offset_from(base) }, 0);
assert_eq!(unsafe { b.as_bitptr().offset_from(base) }, 0);

let (a, b) = bits.split_at(6);
assert_eq!(unsafe { b.as_bitptr().offset_from(base) }, 6);

let (a, b) = bits.split_at(3);
assert_eq!(a, bits![0; 3]);
assert_eq!(b, bits![1; 3]);

pub fn split_at_mut( &mut self, mid: usize, ) -> (&mut BitSlice<<T as BitStore>::Alias, O>, &mut BitSlice<<T as BitStore>::Alias, O>)

Splits a mutable bit-slice in two parts at an index.

The returned bit-slices are self[.. mid] and self[mid ..]. mid is included in the right bit-slice, not the left.

If mid is 0 then the left bit-slice is empty; if it is self.len() then the right bit-slice is empty.

This method guarantees that even when either partition is empty, the encoded bit-pointer values of the bit-slice references is &self[0] and &self[mid].

Original

slice::split_at_mut

API Differences

The end bits of the left half and the start bits of the right half might be stored in the same memory element. In order to avoid breaking bitvec’s memory-safety guarantees, both bit-slices are marked as T::Alias. This marking allows them to be used without interfering with each other when they interact with memory.

Panics

This panics if mid is greater than self.len(). It is allowed to be equal to the length, in which case the right bit-slice is simply empty.

Examples

use bitvec::prelude::*;

let bits = bits![mut u8, Msb0; 0; 6];
let base = bits.as_mut_bitptr();

let (a, b) = bits.split_at_mut(0);
assert_eq!(unsafe { a.as_mut_bitptr().offset_from(base) }, 0);
assert_eq!(unsafe { b.as_mut_bitptr().offset_from(base) }, 0);

let (a, b) = bits.split_at_mut(6);
assert_eq!(unsafe { b.as_mut_bitptr().offset_from(base) }, 6);

let (a, b) = bits.split_at_mut(3);
a.store(3);
b.store(5);

assert_eq!(bits, bits![0, 1, 1, 1, 0, 1]);

pub fn split<F>(&self, pred: F) -> Split<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over subslices separated by bits that match a predicate. The matched bit is not contained in the yielded bit-slices.

Original

slice::split

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .split_mut() has the same splitting logic, but each yielded bit-slice is mutable.
• .split_inclusive() includes the matched bit in the yielded bit-slice.
• .rsplit() iterates from the back of the bit-slice instead of the front.
• .splitn() times out after n yields.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 1, 0];
//                     ^
let mut iter = bits.split(|pos, _bit| pos % 3 == 2);

assert_eq!(iter.next().unwrap(), bits![0, 1]);
assert_eq!(iter.next().unwrap(), bits![0]);
assert!(iter.next().is_none());

If the first bit is matched, then an empty bit-slice will be the first item yielded by the iterator. Similarly, if the last bit in the bit-slice matches, then an empty bit-slice will be the last item yielded.

use bitvec::prelude::*;

let bits = bits![0, 0, 1];
//                     ^
let mut iter = bits.split(|_pos, bit| *bit);

assert_eq!(iter.next().unwrap(), bits![0; 2]);
assert!(iter.next().unwrap().is_empty());
assert!(iter.next().is_none());

If two matched bits are directly adjacent, then an empty bit-slice will be yielded between them:

use bitvec::prelude::*;

let bits = bits![1, 0, 0, 1];
//                  ^  ^
let mut iter = bits.split(|_pos, bit| !*bit);

assert_eq!(iter.next().unwrap(), bits![1]);
assert!(iter.next().unwrap().is_empty());
assert_eq!(iter.next().unwrap(), bits![1]);
assert!(iter.next().is_none());

pub fn split_mut<F>(&mut self, pred: F) -> SplitMut<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over mutable subslices separated by bits that match a predicate. The matched bit is not contained in the yielded bit-slices.

Iterators do not require that each yielded item is destroyed before the next is produced. This means that each bit-slice yielded must be marked as aliased. If you are using this in a loop that does not collect multiple yielded subslices for the same scope, then you can remove the alias marking by calling the (unsafe) method .remove_alias() on the iterator.

Original

slice::split_mut

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .split() has the same splitting logic, but each yielded bit-slice is immutable.
• .split_inclusive_mut() includes the matched bit in the yielded bit-slice.
• .rsplit_mut() iterates from the back of the bit-slice instead of the front.
• .splitn_mut() times out after n yields.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 0, 1, 0, 1, 0];
//                         ^     ^
for group in bits.split_mut(|_pos, bit| *bit) {
  group.set(0, true);
}
assert_eq!(bits, bits![1, 0, 1, 1, 1, 1]);

pub fn split_inclusive<F>(&self, pred: F) -> SplitInclusive<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over subslices separated by bits that match a predicate. Unlike .split(), this does include the matching bit as the last bit in the yielded bit-slice.

Original

slice::split_inclusive

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .split_inclusive_mut() has the same splitting logic, but each yielded bit-slice is mutable.
• .split() does not include the matched bit in the yielded bit-slice.

Examples

use bitvec::prelude::*;

let bits = bits![0, 0, 1, 0, 1];
//                     ^     ^
let mut iter = bits.split_inclusive(|_pos, bit| *bit);

assert_eq!(iter.next().unwrap(), bits![0, 0, 1]);
assert_eq!(iter.next().unwrap(), bits![0, 1]);
assert!(iter.next().is_none());

pub fn split_inclusive_mut<F>( &mut self, pred: F, ) -> SplitInclusiveMut<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over mutable subslices separated by bits that match a predicate. Unlike .split_mut(), this does include the matching bit as the last bit in the bit-slice.

Iterators do not require that each yielded item is destroyed before the next is produced. This means that each bit-slice yielded must be marked as aliased. If you are using this in a loop that does not collect multiple yielded subslices for the same scope, then you can remove the alias marking by calling the (unsafe) method .remove_alias() on the iterator.

Original

slice::split_inclusive_mut

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .split_inclusive() has the same splitting logic, but each yielded bit-slice is immutable.
• .split_mut() does not include the matched bit in the yielded bit-slice.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 0, 0, 0, 0];
//                         ^
for group in bits.split_inclusive_mut(|pos, _bit| pos % 3 == 2) {
  group.set(0, true);
}
assert_eq!(bits, bits![1, 0, 0, 1, 0]);

pub fn rsplit<F>(&self, pred: F) -> RSplit<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over subslices separated by bits that match a predicate, from the back edge. The matched bit is not contained in the yielded bit-slices.

Original

slice::rsplit

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .rsplit_mut() has the same splitting logic, but each yielded bit-slice is mutable.
• .split() iterates from the front of the bit-slice instead of the back.
• .rsplitn() times out after n yields.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 1, 0];
//                     ^
let mut iter = bits.rsplit(|pos, _bit| pos % 3 == 2);

assert_eq!(iter.next().unwrap(), bits![0]);
assert_eq!(iter.next().unwrap(), bits![0, 1]);
assert!(iter.next().is_none());

If the last bit is matched, then an empty bit-slice will be the first item yielded by the iterator. Similarly, if the first bit in the bit-slice matches, then an empty bit-slice will be the last item yielded.

use bitvec::prelude::*;

let bits = bits![0, 0, 1];
//                     ^
let mut iter = bits.rsplit(|_pos, bit| *bit);

assert!(iter.next().unwrap().is_empty());
assert_eq!(iter.next().unwrap(), bits![0; 2]);
assert!(iter.next().is_none());

If two yielded bits are directly adjacent, then an empty bit-slice will be yielded between them:

use bitvec::prelude::*;

let bits = bits![1, 0, 0, 1];
//                  ^  ^
let mut iter = bits.split(|_pos, bit| !*bit);

assert_eq!(iter.next().unwrap(), bits![1]);
assert!(iter.next().unwrap().is_empty());
assert_eq!(iter.next().unwrap(), bits![1]);
assert!(iter.next().is_none());

pub fn rsplit_mut<F>(&mut self, pred: F) -> RSplitMut<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over mutable subslices separated by bits that match a predicate, from the back. The matched bit is not contained in the yielded bit-slices.

Iterators do not require that each yielded item is destroyed before the next is produced. This means that each bit-slice yielded must be marked as aliased. If you are using this in a loop that does not collect multiple yielded subslices for the same scope, then you can remove the alias marking by calling the (unsafe) method .remove_alias() on the iterator.

Original

slice::rsplit_mut

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .rsplit() has the same splitting logic, but each yielded bit-slice is immutable.
• .split_mut() iterates from the front of the bit-slice to the back.
• .rsplitn_mut() iterates from the front of the bit-slice to the back.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 0, 1, 0, 1, 0];
//                         ^     ^
for group in bits.rsplit_mut(|_pos, bit| *bit) {
  group.set(0, true);
}
assert_eq!(bits, bits![1, 0, 1, 1, 1, 1]);

pub fn splitn<F>(&self, n: usize, pred: F) -> SplitN<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over subslices separated by bits that match a predicate, giving up after yielding n times. The nth yield contains the rest of the bit-slice. As with .split(), the yielded bit-slices do not contain the matched bit.

Original

slice::splitn

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .splitn_mut() has the same splitting logic, but each yielded bit-slice is mutable.
• .rsplitn() iterates from the back of the bit-slice instead of the front.
• .split() has the same splitting logic, but never times out.

Examples

use bitvec::prelude::*;

let bits = bits![0, 0, 1, 0, 1, 0];
let mut iter = bits.splitn(2, |_pos, bit| *bit);

assert_eq!(iter.next().unwrap(), bits![0, 0]);
assert_eq!(iter.next().unwrap(), bits![0, 1, 0]);
assert!(iter.next().is_none());

pub fn splitn_mut<F>(&mut self, n: usize, pred: F) -> SplitNMut<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over mutable subslices separated by bits that match a predicate, giving up after yielding n times. The nth yield contains the rest of the bit-slice. As with .split_mut(), the yielded bit-slices do not contain the matched bit.

Iterators do not require that each yielded item is destroyed before the next is produced. This means that each bit-slice yielded must be marked as aliased. If you are using this in a loop that does not collect multiple yielded subslices for the same scope, then you can remove the alias marking by calling the (unsafe) method .remove_alias() on the iterator.

Original

slice::splitn_mut

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .splitn() has the same splitting logic, but each yielded bit-slice is immutable.
• .rsplitn_mut() iterates from the back of the bit-slice instead of the front.
• .split_mut() has the same splitting logic, but never times out.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 0, 1, 0, 1, 0];
for group in bits.splitn_mut(2, |_pos, bit| *bit) {
  group.set(0, true);
}
assert_eq!(bits, bits![1, 0, 1, 1, 1, 0]);

pub fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over mutable subslices separated by bits that match a predicate from the back edge, giving up after yielding n times. The nth yield contains the rest of the bit-slice. As with .split_mut(), the yielded bit-slices do not contain the matched bit.

Original

slice::rsplitn

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .rsplitn_mut() has the same splitting logic, but each yielded bit-slice is mutable.
• .splitn(): iterates from the front of the bit-slice instead of the back.
• .rsplit() has the same splitting logic, but never times out.

Examples

use bitvec::prelude::*;

let bits = bits![0, 0, 1, 1, 0];
//                        ^
let mut iter = bits.rsplitn(2, |_pos, bit| *bit);

assert_eq!(iter.next().unwrap(), bits![0]);
assert_eq!(iter.next().unwrap(), bits![0, 0, 1]);
assert!(iter.next().is_none());

pub fn rsplitn_mut<F>(&mut self, n: usize, pred: F) -> RSplitNMut<'_, T, O, F>

where F: FnMut(usize, &bool) -> bool,

Iterates over mutable subslices separated by bits that match a predicate from the back edge, giving up after yielding n times. The nth yield contains the rest of the bit-slice. As with .split_mut(), the yielded bit-slices do not contain the matched bit.

Iterators do not require that each yielded item is destroyed before the next is produced. This means that each bit-slice yielded must be marked as aliased. If you are using this in a loop that does not collect multiple yielded subslices for the same scope, then you can remove the alias marking by calling the (unsafe) method .remove_alias() on the iterator.

Original

slice::rsplitn_mut

API Differences

The predicate function receives the index being tested as well as the bit value at that index. This allows the predicate to have more than one bit of information about the bit-slice being traversed.

Sibling Methods

• .rsplitn() has the same splitting logic, but each yielded bit-slice is immutable.
• .splitn_mut() iterates from the front of the bit-slice instead of the back.
• .rsplit_mut() has the same splitting logic, but never times out.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 0, 1, 0, 0, 1, 0, 0, 0];
for group in bits.rsplitn_mut(2, |_idx, bit| *bit) {
  group.set(0, true);
}
assert_eq!(bits, bits![1, 0, 1, 0, 0, 1, 1, 0, 0]);
//                     ^ group 2         ^ group 1

pub fn contains<T2, O2>(&self, other: &BitSlice<T2, O2>) -> bool

where T2: BitStore, O2: BitOrder,

Tests if the bit-slice contains the given sequence anywhere within it.

This scans over self.windows(other.len()) until one of the windows matches. The search key does not need to share type parameters with the bit-slice being tested, as the comparison is bit-wise. However, sharing type parameters will accelerate the comparison.

Original

slice::contains

Examples

use bitvec::prelude::*;

let bits = bits![0, 0, 1, 0, 1, 1, 0, 0];
assert!( bits.contains(bits![0, 1, 1, 0]));
assert!(!bits.contains(bits![1, 0, 0, 1]));

pub fn starts_with<T2, O2>(&self, needle: &BitSlice<T2, O2>) -> bool

where T2: BitStore, O2: BitOrder,

Tests if the bit-slice begins with the given sequence.

The search key does not need to share type parameters with the bit-slice being tested, as the comparison is bit-wise. However, sharing type parameters will accelerate the comparison.

Original

slice::starts_with

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 1, 0];
assert!( bits.starts_with(bits![0, 1]));
assert!(!bits.starts_with(bits![1, 0]));

This always returns true if the needle is empty:

use bitvec::prelude::*;

let bits = bits![0, 1, 0];
let empty = bits![];
assert!(bits.starts_with(empty));
assert!(empty.starts_with(empty));

pub fn ends_with<T2, O2>(&self, needle: &BitSlice<T2, O2>) -> bool

where T2: BitStore, O2: BitOrder,

Tests if the bit-slice ends with the given sequence.

The search key does not need to share type parameters with the bit-slice being tested, as the comparison is bit-wise. However, sharing type parameters will accelerate the comparison.

Original

slice::ends_with

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 1, 0];
assert!( bits.ends_with(bits![1, 0]));
assert!(!bits.ends_with(bits![0, 1]));

This always returns true if the needle is empty:

use bitvec::prelude::*;

let bits = bits![0, 1, 0];
let empty = bits![];
assert!(bits.ends_with(empty));
assert!(empty.ends_with(empty));

pub fn strip_prefix<T2, O2>( &self, prefix: &BitSlice<T2, O2>, ) -> Option<&BitSlice<T, O>>

where T2: BitStore, O2: BitOrder,

Removes a prefix bit-slice, if present.

Like .starts_with(), the search key does not need to share type parameters with the bit-slice being stripped. If self.starts_with(suffix), then this returns Some(&self[prefix.len() ..]), otherwise it returns None.

Original

slice::strip_prefix

API Differences

BitSlice does not support pattern searches; instead, it permits self and prefix to differ in type parameters.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1, 0, 1, 1, 0];
assert_eq!(bits.strip_prefix(bits![0, 1]).unwrap(), bits[2 ..]);
assert_eq!(bits.strip_prefix(bits![0, 1, 0, 0,]).unwrap(), bits[4 ..]);
assert!(bits.strip_prefix(bits![1, 0]).is_none());

pub fn strip_suffix<T2, O2>( &self, suffix: &BitSlice<T2, O2>, ) -> Option<&BitSlice<T, O>>

where T2: BitStore, O2: BitOrder,

Removes a suffix bit-slice, if present.

Like .ends_with(), the search key does not need to share type parameters with the bit-slice being stripped. If self.ends_with(suffix), then this returns Some(&self[.. self.len() - suffix.len()]), otherwise it returns None.

Original

slice::strip_suffix

API Differences

BitSlice does not support pattern searches; instead, it permits self and suffix to differ in type parameters.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1, 0, 1, 1, 0];
assert_eq!(bits.strip_suffix(bits![1, 0]).unwrap(), bits[.. 7]);
assert_eq!(bits.strip_suffix(bits![0, 1, 1, 0]).unwrap(), bits[.. 5]);
assert!(bits.strip_suffix(bits![0, 1]).is_none());

pub fn rotate_left(&mut self, by: usize)

Rotates the contents of a bit-slice to the left (towards the zero index).

This essentially splits the bit-slice at by, then exchanges the two pieces. self[.. by] becomes the first section, and is then followed by self[.. by].

The implementation is batch-accelerated where possible. It should have a runtime complexity much lower than O(by).

Original

slice::rotate_left

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 0, 1, 0, 1, 0];
//      split occurs here ^
bits.rotate_left(2);
assert_eq!(bits, bits![1, 0, 1, 0, 0, 0]);

pub fn rotate_right(&mut self, by: usize)

Rotates the contents of a bit-slice to the right (away from the zero index).

This essentially splits the bit-slice at self.len() - by, then exchanges the two pieces. self[len - by ..] becomes the first section, and is then followed by self[.. len - by].

The implementation is batch-accelerated where possible. It should have a runtime complexity much lower than O(by).

Original

slice::rotate_right

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 0, 1, 1, 1, 0];
//            split occurs here ^
bits.rotate_right(2);
assert_eq!(bits, bits![1, 0, 0, 0, 1, 1]);

pub fn fill(&mut self, value: bool)

Fills the bit-slice with a given bit.

This is a recent stabilization in the standard library. bitvec previously offered this behavior as the novel API .set_all(). That method name is now removed in favor of this standard-library analogue.

Original

slice::fill

Examples

use bitvec::prelude::*;

let bits = bits![mut 0; 5];
bits.fill(true);
assert_eq!(bits, bits![1; 5]);

pub fn fill_with<F>(&mut self, func: F)

where F: FnMut(usize) -> bool,

Fills the bit-slice with bits produced by a generator function.

Original

slice::fill_with

API Differences

The generator function receives the index of the bit being initialized as an argument.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0; 5];
bits.fill_with(|idx| idx % 2 == 0);
assert_eq!(bits, bits![1, 0, 1, 0, 1]);

pub fn clone_from_slice<T2, O2>(&mut self, src: &BitSlice<T2, O2>)

where T2: BitStore, O2: BitOrder,

👎Deprecated: use .clone_from_bitslice() instead

pub fn copy_from_slice(&mut self, src: &BitSlice<T, O>)

👎Deprecated: use .copy_from_bitslice() instead

pub fn copy_within<R>(&mut self, src: R, dest: usize)

where R: RangeExt<usize>,

Copies a span of bits to another location in the bit-slice.

src is the range of bit-indices in the bit-slice to copy, and dest is the starting index of the destination range. srcanddest .. dest + src.len()are permitted to overlap; the copy will automatically detect and manage this. However, bothsrcanddest .. dest + src.len()**must** fall within the bounds ofself`.

Original

slice::copy_within

Panics

This panics if either the source or destination range exceed self.len().

Examples

use bitvec::prelude::*;

let bits = bits![mut 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0];
bits.copy_within(1 .. 5, 8);
//                        v  v  v  v
assert_eq!(bits, bits![1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0]);
//                                             ^  ^  ^  ^

pub fn swap_with_slice<T2, O2>(&mut self, other: &mut BitSlice<T2, O2>)

where T2: BitStore, O2: BitOrder,

👎Deprecated: use .swap_with_bitslice() instead

pub unsafe fn align_to<U>( &self, ) -> (&BitSlice<T, O>, &BitSlice<U, O>, &BitSlice<T, O>)

where U: BitStore,

Produces bit-slice view(s) with different underlying storage types.

This may have unexpected effects, and you cannot assume that before[idx] == after[idx]! Consult the tables in the manual for information about memory layouts.

Original

slice::align_to

Notes

Unlike the standard library documentation, this explicitly guarantees that the middle bit-slice will have maximal size. You may rely on this property.

Safety

You may not use this to cast away alias protections. Rust does not have support for higher-kinded types, so this cannot express the relation Outer<T> -> Outer<U> where Outer: BitStoreContainer, but memory safety does require that you respect this rule. Reälign integers to integers, Cells to Cells, and atomics to atomics, but do not cross these boundaries.

Examples

use bitvec::prelude::*;

let bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
let bits = bytes.view_bits::<Lsb0>();
let (pfx, mid, sfx) = unsafe {
  bits.align_to::<u16>()
};
assert!(pfx.len() <= 8);
assert_eq!(mid.len(), 48);
assert!(sfx.len() <= 8);

pub unsafe fn align_to_mut<U>( &mut self, ) -> (&mut BitSlice<T, O>, &mut BitSlice<U, O>, &mut BitSlice<T, O>)

where U: BitStore,

Produces bit-slice view(s) with different underlying storage types.

This may have unexpected effects, and you cannot assume that before[idx] == after[idx]! Consult the tables in the manual for information about memory layouts.

Original

slice::align_to_mut

Notes

Unlike the standard library documentation, this explicitly guarantees that the middle bit-slice will have maximal size. You may rely on this property.

Safety

You may not use this to cast away alias protections. Rust does not have support for higher-kinded types, so this cannot express the relation Outer<T> -> Outer<U> where Outer: BitStoreContainer, but memory safety does require that you respect this rule. Reälign integers to integers, Cells to Cells, and atomics to atomics, but do not cross these boundaries.

Examples

use bitvec::prelude::*;

let mut bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
let bits = bytes.view_bits_mut::<Lsb0>();
let (pfx, mid, sfx) = unsafe {
  bits.align_to_mut::<u16>()
};
assert!(pfx.len() <= 8);
assert_eq!(mid.len(), 48);
assert!(sfx.len() <= 8);

pub fn to_vec(&self) -> BitVec<<T as BitStore>::Unalias, O>

👎Deprecated: use .to_bitvec() instead

pub fn repeat(&self, n: usize) -> BitVec<<T as BitStore>::Unalias, O>

Creates a bit-vector by repeating a bit-slice n times.

Original

slice::repeat

Panics

This method panics if self.len() * n exceeds the BitVec capacity.

Examples

use bitvec::prelude::*;

assert_eq!(bits![0, 1].repeat(3), bitvec![0, 1, 0, 1, 0, 1]);

This panics by exceeding bit-vector maximum capacity:

use bitvec::prelude::*;

bits![0, 1].repeat(BitSlice::<usize, Lsb0>::MAX_BITS);

pub fn as_bitptr(&self) -> BitPtr<Const, T, O>

Gets a raw pointer to the zeroth bit of the bit-slice.

Original

slice::as_ptr

API Differences

This is renamed in order to indicate that it is returning a bitvec structure, not a raw pointer.

pub fn as_mut_bitptr(&mut self) -> BitPtr<Mut, T, O>

Gets a raw, write-capable pointer to the zeroth bit of the bit-slice.

Original

slice::as_mut_ptr

API Differences

This is renamed in order to indicate that it is returning a bitvec structure, not a raw pointer.

pub fn as_bitptr_range(&self) -> BitPtrRange<Const, T, O>

Views the bit-slice as a half-open range of bit-pointers, to its first bit in the bit-slice and first bit beyond it.

Original

slice::as_ptr_range

API Differences

This is renamed to indicate that it returns a bitvec structure, rather than an ordinary Range.

Notes

BitSlice does define a .as_ptr_range(), which returns a Range<BitPtr>. BitPtrRange has additional capabilities that Range<*const T> and Range<BitPtr> do not.

pub fn as_mut_bitptr_range(&mut self) -> BitPtrRange<Mut, T, O>

Views the bit-slice as a half-open range of write-capable bit-pointers, to its first bit in the bit-slice and the first bit beyond it.

Original

slice::as_mut_ptr_range

API Differences

This is renamed to indicate that it returns a bitvec structure, rather than an ordinary Range.

Notes

BitSlice does define a [.as_mut_ptr_range()], which returns a Range<BitPtr>. BitPtrRange has additional capabilities that Range<*mut T> and Range<BitPtr> do not.

pub fn clone_from_bitslice<T2, O2>(&mut self, src: &BitSlice<T2, O2>)

where T2: BitStore, O2: BitOrder,

Copies the bits from src into self.

self and src must have the same length.

Performance

If src has the same type arguments as self, it will use the same implementation as .copy_from_bitslice(); if you know that this will always be the case, you should prefer to use that method directly.

Only .copy_from_bitslice() is able to perform acceleration; this method is always required to perform a bit-by-bit crawl over both bit-slices.

Original

slice::clone_from_slice

API Differences

This is renamed to reflect that it copies from another bit-slice, not from an element slice.

In order to support general usage, it allows src to have different type parameters than self, at the cost of performance optimizations.

Panics

This panics if the two bit-slices have different lengths.

Examples

use bitvec::prelude::*;

pub fn copy_from_bitslice(&mut self, src: &BitSlice<T, O>)

Copies all bits from src into self, using batched acceleration when possible.

self and src must have the same length.

Original

slice::copy_from_slice

Panics

This panics if the two bit-slices have different lengths.

Examples

use bitvec::prelude::*;

pub fn swap_with_bitslice<T2, O2>(&mut self, other: &mut BitSlice<T2, O2>)

where T2: BitStore, O2: BitOrder,

Swaps the contents of two bit-slices.

self and other must have the same length.

Original

slice::swap_with_slice

API Differences

This method is renamed, as it takes a bit-slice rather than an element slice.

Panics

This panics if the two bit-slices have different lengths.

Examples

use bitvec::prelude::*;

let mut one = [0xA5u8, 0x69];
let mut two = 0x1234u16;
let one_bits = one.view_bits_mut::<Msb0>();
let two_bits = two.view_bits_mut::<Lsb0>();

one_bits.swap_with_bitslice(two_bits);

assert_eq!(one, [0x2C, 0x48]);
assert_eq!(two, 0x96A5);

pub fn set(&mut self, index: usize, value: bool)

Writes a new value into a single bit.

This is the replacement for *slice[index] = value;, as bitvec is not able to express that under the current IndexMut API signature.

Parameters

• &mut self
• index: The bit-index to set. It must be in 0 .. self.len().
• value: The new bit-value to write into the bit at index.

Panics

This panics if index is out of bounds.

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 1];
bits.set(0, true);
bits.set(1, false);

assert_eq!(bits, bits![1, 0]);

pub unsafe fn set_unchecked(&mut self, index: usize, value: bool)

Writes a new value into a single bit, without bounds checking.

Parameters

• &mut self
• index: The bit-index to set. It must be in 0 .. self.len().
• value: The new bit-value to write into the bit at index.

Safety

You must ensure that index is in the range 0 .. self.len().

This performs bit-pointer offset arithmetic without doing any bounds checks. If index is out of bounds, then this will issue an out-of-bounds access and will trigger memory unsafety.

Examples

use bitvec::prelude::*;

let mut data = 0u8;
let bits = &mut data.view_bits_mut::<Lsb0>()[.. 2];
assert_eq!(bits.len(), 2);
unsafe {
  bits.set_unchecked(3, true);
}
assert_eq!(data, 8);

pub fn replace(&mut self, index: usize, value: bool) -> bool

Writes a new value into a bit, and returns its previous value.

Panics

This panics if index is not less than self.len().

Examples

use bitvec::prelude::*;

let bits = bits![mut 0];
assert!(!bits.replace(0, true));
assert!(bits[0]);

pub unsafe fn replace_unchecked(&mut self, index: usize, value: bool) -> bool

Writes a new value into a bit, returning the previous value, without bounds checking.

Safety

index must be less than self.len().

Examples

use bitvec::prelude::*;

let bits = bits![mut 0, 0];
let old = unsafe {
  let a = &mut bits[.. 1];
  a.replace_unchecked(1, true)
};
assert!(!old);
assert!(bits[1]);

pub unsafe fn swap_unchecked(&mut self, a: usize, b: usize)

Swaps two bits in a bit-slice, without bounds checking.

See .swap() for documentation.

Safety

You must ensure that a and b are both in the range 0 .. self.len().

This method performs bit-pointer offset arithmetic without doing any bounds checks. If a or b are out of bounds, then this will issue an out-of-bounds access and will trigger memory unsafety.

pub unsafe fn split_at_unchecked( &self, mid: usize, ) -> (&BitSlice<T, O>, &BitSlice<T, O>)

Splits a bit-slice at an index, without bounds checking.

See .split_at() for documentation.

Safety

You must ensure that mid is in the range 0 ..= self.len().

This method produces new bit-slice references. If mid is out of bounds, its behavior is library-level undefined. You must conservatively assume that an out-of-bounds split point produces compiler-level UB.

pub unsafe fn split_at_unchecked_mut( &mut self, mid: usize, ) -> (&mut BitSlice<<T as BitStore>::Alias, O>, &mut BitSlice<<T as BitStore>::Alias, O>)

Splits a mutable bit-slice at an index, without bounds checking.

See .split_at_mut() for documentation.

Safety

You must ensure that mid is in the range 0 ..= self.len().

This method produces new bit-slice references. If mid is out of bounds, its behavior is library-level undefined. You must conservatively assume that an out-of-bounds split point produces compiler-level UB.

pub unsafe fn copy_within_unchecked<R>(&mut self, src: R, dest: usize)

where R: RangeExt<usize>,

Copies bits from one region of the bit-slice to another region of itself, without doing bounds checks.

The regions are allowed to overlap.

Parameters

• &mut self
• src: The range within self from which to copy.
• dst: The starting index within self at which to paste.

Effects

self[src] is copied to self[dest .. dest + src.len()]. The bits of self[src] are in an unspecified, but initialized, state.

Safety

src.end() and dest + src.len() must be entirely within bounds.

Examples

use bitvec::prelude::*;

let mut data = 0b1011_0000u8;
let bits = data.view_bits_mut::<Msb0>();

unsafe {
  bits.copy_within_unchecked(.. 4, 2);
}
assert_eq!(data, 0b1010_1100);

pub fn bit_domain(&self) -> BitDomain<'_, Const, T, O>

Partitions a bit-slice into maybe-contended and known-uncontended parts.

The documentation of BitDomain goes into this in more detail. In short, this produces a &BitSlice that is as large as possible without requiring alias protection, as well as any bits that were not able to be included in the unaliased bit-slice.

pub fn bit_domain_mut(&mut self) -> BitDomain<'_, Mut, T, O>

Partitions a mutable bit-slice into maybe-contended and known-uncontended parts.

The documentation of BitDomain goes into this in more detail. In short, this produces a &mut BitSlice that is as large as possible without requiring alias protection, as well as any bits that were not able to be included in the unaliased bit-slice.

pub fn domain(&self) -> Domain<'_, Const, T, O>

Views the underlying memory of a bit-slice, removing alias protections where possible.

The documentation of Domain goes into this in more detail. In short, this produces a &[T] slice with alias protections removed, covering all elements that self completely fills. Partially-used elements on either the front or back edge of the slice are returned separately.

pub fn domain_mut(&mut self) -> Domain<'_, Mut, T, O>

Views the underlying memory of a bit-slice, removing alias protections where possible.

The documentation of Domain goes into this in more detail. In short, this produces a &mut [T] slice with alias protections removed, covering all elements that self completely fills. Partially-used elements on the front or back edge of the slice are returned separately.

pub fn count_ones(&self) -> usize

Counts the number of bits set to 1 in the bit-slice contents.

Examples

use bitvec::prelude::*;

let bits = bits![1, 1, 0, 0];
assert_eq!(bits[.. 2].count_ones(), 2);
assert_eq!(bits[2 ..].count_ones(), 0);
assert_eq!(bits![].count_ones(), 0);

pub fn count_zeros(&self) -> usize

Counts the number of bits cleared to 0 in the bit-slice contents.

Examples

use bitvec::prelude::*;

let bits = bits![1, 1, 0, 0];
assert_eq!(bits[.. 2].count_zeros(), 0);
assert_eq!(bits[2 ..].count_zeros(), 2);
assert_eq!(bits![].count_zeros(), 0);

pub fn iter_ones(&self) -> IterOnes<'_, T, O>

Enumerates the index of each bit in a bit-slice set to 1.

This is a shorthand for a .enumerate().filter_map() iterator that selects the index of each true bit; however, its implementation is eligible for optimizations that the individual-bit iterator is not.

Specializations for the Lsb0 and Msb0 orderings allow processors with instructions that seek particular bits within an element to operate on whole elements, rather than on each bit individually.

Examples

This example uses .iter_ones(), a .filter_map() that finds the index of each set bit, and the known indices, in order to show that they have equivalent behavior.

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1, 0, 0, 0, 1];

let iter_ones = bits.iter_ones();
let known_indices = [1, 4, 8].iter().copied();
let filter = bits.iter()
  .by_vals()
  .enumerate()
  .filter_map(|(idx, bit)| if bit { Some(idx) } else { None });
let all = iter_ones.zip(known_indices).zip(filter);

for ((iter_one, known), filtered) in all {
  assert_eq!(iter_one, known);
  assert_eq!(known, filtered);
}

pub fn iter_zeros(&self) -> IterZeros<'_, T, O>

Enumerates the index of each bit in a bit-slice cleared to 0.

This is a shorthand for a .enumerate().filter_map() iterator that selects the index of each false bit; however, its implementation is eligible for optimizations that the individual-bit iterator is not.

Specializations for the Lsb0 and Msb0 orderings allow processors with instructions that seek particular bits within an element to operate on whole elements, rather than on each bit individually.

Examples

This example uses .iter_zeros(), a .filter_map() that finds the index of each cleared bit, and the known indices, in order to show that they have equivalent behavior.

use bitvec::prelude::*;

let bits = bits![1, 0, 1, 1, 0, 1, 1, 1, 0];

let iter_zeros = bits.iter_zeros();
let known_indices = [1, 4, 8].iter().copied();
let filter = bits.iter()
  .by_vals()
  .enumerate()
  .filter_map(|(idx, bit)| if !bit { Some(idx) } else { None });
let all = iter_zeros.zip(known_indices).zip(filter);

for ((iter_zero, known), filtered) in all {
  assert_eq!(iter_zero, known);
  assert_eq!(known, filtered);
}

pub fn first_one(&self) -> Option<usize>

Finds the index of the first bit in the bit-slice set to 1.

Returns None if there is no true bit in the bit-slice.

Examples

use bitvec::prelude::*;

assert!(bits![].first_one().is_none());
assert!(bits![0].first_one().is_none());
assert_eq!(bits![0, 1].first_one(), Some(1));

pub fn first_zero(&self) -> Option<usize>

Finds the index of the first bit in the bit-slice cleared to 0.

Returns None if there is no false bit in the bit-slice.

Examples

use bitvec::prelude::*;

assert!(bits![].first_zero().is_none());
assert!(bits![1].first_zero().is_none());
assert_eq!(bits![1, 0].first_zero(), Some(1));

pub fn last_one(&self) -> Option<usize>

Finds the index of the last bit in the bit-slice set to 1.

Returns None if there is no true bit in the bit-slice.

Examples

use bitvec::prelude::*;

assert!(bits![].last_one().is_none());
assert!(bits![0].last_one().is_none());
assert_eq!(bits![1, 0].last_one(), Some(0));

pub fn last_zero(&self) -> Option<usize>

Finds the index of the last bit in the bit-slice cleared to 0.

Returns None if there is no false bit in the bit-slice.

Examples

use bitvec::prelude::*;

assert!(bits![].last_zero().is_none());
assert!(bits![1].last_zero().is_none());
assert_eq!(bits![0, 1].last_zero(), Some(0));

pub fn leading_ones(&self) -> usize

Counts the number of bits from the start of the bit-slice to the first bit set to 0.

This returns 0 if the bit-slice is empty.

Examples

use bitvec::prelude::*;

assert_eq!(bits![].leading_ones(), 0);
assert_eq!(bits![0].leading_ones(), 0);
assert_eq!(bits![1, 0].leading_ones(), 1);

pub fn leading_zeros(&self) -> usize

Counts the number of bits from the start of the bit-slice to the first bit set to 1.

This returns 0 if the bit-slice is empty.

Examples

use bitvec::prelude::*;

assert_eq!(bits![].leading_zeros(), 0);
assert_eq!(bits![1].leading_zeros(), 0);
assert_eq!(bits![0, 1].leading_zeros(), 1);

pub fn trailing_ones(&self) -> usize

Counts the number of bits from the end of the bit-slice to the last bit set to 0.

This returns 0 if the bit-slice is empty.

Examples

use bitvec::prelude::*;

assert_eq!(bits![].trailing_ones(), 0);
assert_eq!(bits![0].trailing_ones(), 0);
assert_eq!(bits![0, 1].trailing_ones(), 1);

pub fn trailing_zeros(&self) -> usize

Counts the number of bits from the end of the bit-slice to the last bit set to 1.

This returns 0 if the bit-slice is empty.

Examples

use bitvec::prelude::*;

assert_eq!(bits![].trailing_zeros(), 0);
assert_eq!(bits![1].trailing_zeros(), 0);
assert_eq!(bits![1, 0].trailing_zeros(), 1);

pub fn any(&self) -> bool

Tests if there is at least one bit set to 1 in the bit-slice.

Returns false when self is empty.

Examples

use bitvec::prelude::*;

assert!(!bits![].any());
assert!(!bits![0].any());
assert!(bits![0, 1].any());

pub fn all(&self) -> bool

Tests if every bit is set to 1 in the bit-slice.

Returns true when self is empty.

Examples

use bitvec::prelude::*;

assert!( bits![].all());
assert!(!bits![0].all());
assert!( bits![1].all());

pub fn not_any(&self) -> bool

Tests if every bit is cleared to 0 in the bit-slice.

Returns true when self is empty.

Examples

use bitvec::prelude::*;

assert!( bits![].not_any());
assert!(!bits![1].not_any());
assert!( bits![0].not_any());

pub fn not_all(&self) -> bool

Tests if at least one bit is cleared to 0 in the bit-slice.

Returns false when self is empty.

Examples

use bitvec::prelude::*;

assert!(!bits![].not_all());
assert!(!bits![1].not_all());
assert!( bits![0].not_all());

pub fn some(&self) -> bool

Tests if at least one bit is set to 1, and at least one bit is cleared to 0, in the bit-slice.

Returns false when self is empty.

Examples

use bitvec::prelude::*;

assert!(!bits![].some());
assert!(!bits![0].some());
assert!(!bits![1].some());
assert!( bits![0, 1].some());

pub fn shift_left(&mut self, by: usize)

Shifts the contents of a bit-slice “left” (towards the zero-index), clearing the “right” bits to 0.

This is a strictly-worse analogue to taking bits = &bits[by ..]: it has to modify the entire memory region that bits governs, and destroys contained information. Unless the actual memory layout and contents of your bit-slice matters to your program, you should probably prefer to munch your way forward through a bit-slice handle.

Note also that the “left” here is semantic only, and does not necessarily correspond to a left-shift instruction applied to the underlying integer storage.

This has no effect when by is 0. When by is self.len(), the bit-slice is entirely cleared to 0.

Panics

This panics if by is not less than self.len().

Examples

use bitvec::prelude::*;

let bits = bits![mut 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1];
// these bits are retained ^--------------------------^
bits.shift_left(2);
assert_eq!(bits, bits![1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0]);
// and move here       ^--------------------------^

let bits = bits![mut 1; 2];
bits.shift_left(2);
assert_eq!(bits, bits![0; 2]);

pub fn shift_right(&mut self, by: usize)

Shifts the contents of a bit-slice “right” (away from the zero-index), clearing the “left” bits to 0.

This is a strictly-worse analogue to taking `bits = &bits[.. bits.len()

• by]: it must modify the entire memory region that bits` governs, and destroys contained information. Unless the actual memory layout and contents of your bit-slice matters to your program, you should probably prefer to munch your way backward through a bit-slice handle.

Note also that the “right” here is semantic only, and does not necessarily correspond to a right-shift instruction applied to the underlying integer storage.

This has no effect when by is 0. When by is self.len(), the bit-slice is entirely cleared to 0.

Panics

This panics if by is not less than self.len().

Examples

use bitvec::prelude::*;

let bits = bits![mut 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1];
// these bits stay   ^--------------------------^
bits.shift_right(2);
assert_eq!(bits, bits![0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1]);
// and move here             ^--------------------------^

let bits = bits![mut 1; 2];
bits.shift_right(2);
assert_eq!(bits, bits![0; 2]);

pub fn set_aliased(&self, index: usize, value: bool)

Writes a new value into a single bit, using alias-safe operations.

This is equivalent to .set(), except that it does not require an &mut reference, and allows bit-slices with alias-safe storage to share write permissions.

Parameters

• &self: This method only exists on bit-slices with alias-safe storage, and so does not require exclusive access.
• index: The bit index to set. It must be in 0 .. self.len().
• value: The new bit-value to write into the bit at index.

Panics

This panics if index is out of bounds.

Examples

use bitvec::prelude::*;
use core::cell::Cell;

let bits: &BitSlice<_, _> = bits![Cell<usize>, Lsb0; 0, 1];
bits.set_aliased(0, true);
bits.set_aliased(1, false);

assert_eq!(bits, bits![1, 0]);

pub unsafe fn set_aliased_unchecked(&self, index: usize, value: bool)

Writes a new value into a single bit, using alias-safe operations and without bounds checking.

This is equivalent to .set_unchecked(), except that it does not require an &mut reference, and allows bit-slices with alias-safe storage to share write permissions.

Parameters

• &self: This method only exists on bit-slices with alias-safe storage, and so does not require exclusive access.
• index: The bit index to set. It must be in 0 .. self.len().
• value: The new bit-value to write into the bit at index.

Safety

The caller must ensure that index is not out of bounds.

Examples

use bitvec::prelude::*;
use core::cell::Cell;

let data = Cell::new(0u8);
let bits = &data.view_bits::<Lsb0>()[.. 2];
unsafe {
  bits.set_aliased_unchecked(3, true);
}
assert_eq!(data.get(), 8);

pub const MAX_BITS: usize = 2_305_843_009_213_693_951usize

pub const MAX_ELTS: usize = BitSpan<Const, T, O>::REGION_MAX_ELTS

pub fn to_bitvec(&self) -> BitVec<<T as BitStore>::Unalias, O>

Copies a bit-slice into an owned bit-vector.

Since the new vector is freshly owned, this gets marked as ::Unalias to remove any guards that may have been inserted by the bit-slice’s history.

It does not use the underlying memory type, so that a BitSlice<_, Cell<_>> will produce a BitVec<_, Cell<_>>.

Original

slice::to_vec

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 1];
let bv = bits.to_bitvec();
assert_eq!(bits, bv);

Trait Implementations

impl<const N: usize> Clone for Bitvector<N>

fn clone(&self) -> Bitvector<N>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<const N: usize> Debug for Bitvector<N>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<const N: usize> Default for Bitvector<N>

fn default() -> Self

Returns the “default value” for a type.

impl<const N: usize> Deref for Bitvector<N>

type Target = BitVec<u8>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<const N: usize> DerefMut for Bitvector<N>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<'de, const N: usize> Deserialize<'de> for Bitvector<N>

Available on crate feature serde only.

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<const N: usize> Deserialize for Bitvector<N>

fn deserialize(encoding: &[u8]) -> Result<Self, DeserializeError>

Deserialize this value from the given SSZ-encoded buffer.

impl<const N: usize> Merkleized for Bitvector<N>

fn hash_tree_root(&mut self) -> Result<Node, MerkleizationError>

Compute the “hash tree root” of Self.

impl<const N: usize> PartialEq for Bitvector<N>

fn eq(&self, other: &Bitvector<N>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<const N: usize> Serialize for Bitvector<N>

Available on crate feature serde only.

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<const N: usize> Serialize for Bitvector<N>

fn serialize(&self, buffer: &mut Vec<u8>) -> Result<usize, SerializeError>

Append an encoding of self to the buffer.

impl<const N: usize> SimpleSerialize for Bitvector<N>

fn is_composite_type() -> bool

impl<const N: usize> Sized for Bitvector<N>

fn is_variable_size() -> bool

fn size_hint() -> usize

impl<const N: usize> TryFrom<&[bool]> for Bitvector<N>

type Error = Error

The type returned in the event of a conversion error.

fn try_from(value: &[bool]) -> Result<Self, Self::Error>

Performs the conversion.

impl<const N: usize> TryFrom<&[u8]> for Bitvector<N>

type Error = Error

The type returned in the event of a conversion error.

fn try_from(value: &[u8]) -> Result<Self, Self::Error>

Performs the conversion.

impl<const N: usize> Eq for Bitvector<N>

impl<const N: usize> StructuralPartialEq for Bitvector<N>