Struct bitvec::boxed::BitBox

#[repr(transparent)]pub struct BitBox<O = Lsb0, T = usize> where
    O: BitOrder,
    T: BitStore,  { /* fields omitted */ }

A frozen heap-allocated buffer of individual bits.

This is essentially a BitVec that has frozen its allocation, and given up the ability to change size. It is analagous to Box<[bool]>. You should prefer BitArray over BitBox where possible, and may freely box it if you need the indirection.

Documentation

All APIs that mirror something in the standard library will have an Original section linking to the corresponding item. All APIs that have a different signature or behavior than the original will have an API Differences section explaining what has changed, and how to adapt your existing code to the change.

These sections look like this:

Original

Box<[T]>

API Differences

The buffer type Box<[bool]> has no type parameters. BitBox<O, T> has the same two type parameters as BitSlice<O, T>. Otherwise, BitBox is able to implement the full API surface of Box<[bool]>.

Behavior

Because BitBox is a fully-owned buffer, it is able to operate on its memory without concern for any other views that may alias. This enables it to specialize some BitSlice behavior to be faster or more efficient.

Type Parameters

This takes the same BitOrder and BitStore parameters as BitSlice. Unlike BitSlice, it is restricted to only accept the fundamental integers as its BitStore arguments; BitBox buffers can never be aliased by other BitBoxes, and do not need to share memory access.

Safety

BitBox is a wrapper over a NonNull<BitSlice<O, T>> pointer; this allows it to remain exactly two words in size, and means that it is subject to the same representational incompatibility restrictions as BitSlice references. You must never attempt to type-cast between Box<[bool]> and BitBox in any way, nor may you attempt to modify the memory value of a BitBox handle. Doing so will cause allocator and memory errors in your program, likely inducing a panic.

Everything in the BitBox public API, even the unsafe parts, are guaranteed to have no more unsafety or potential for incorrectness than their equivalent items in the standard library. All unsafe APIs will have documentation explicitly detailing what the API requires you to uphold in order for it to function safely and correctly. All safe APIs will do so themselves.

Macro Construction

Heap allocation can only occur at runtime, but the bitbox! macro will construct an appropriate BitSlice buffer at compile-time, and at run-time, only copy the buffer into a heap allocation.

Implementations

impl<O, T> BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

pub fn new(x: &BitSlice<O, T>) -> Self

👎 Deprecated:

Prefer from_bitslice

Allocates memory on the heap and then copies x into it.

This doesn’t actually allocate if x is zero-length.

Original

Box::new

API Differences

Box::<[T]>::new does not exist, because unsized types cannot be taken by value. Instead, this takes a slice reference, and boxes the referent slice.

Examples

use bitvec::prelude::*;

let boxed = BitBox::new(bits![0; 5]);

pub fn pin(x: &BitSlice<O, T>) -> Pin<Self> where
    O: Unpin,
    T: Unpin, 

Constructs a new Pin<BitBox<O, T>>.

BitSlice is always Unpin, so this has no actual effect.

Original

Box::pin

API Differences

As with new, this only exists on Box when T is not unsized. This takes a slice reference, and pins the referent slice.

pub unsafe fn from_raw(raw: *mut BitSlice<O, T>) -> Self

Constructs a bit-box from a raw bit-slice pointer.

After calling this function, the raw bit-slice pointer is owned by the resulting BitBox. Specifically, the BitBox destructor will free the memory allocation at the bit-slice pointer’s address. For this to be safe, the bit-slice pointer can only have been produced by a BitBox previously destroyed using into_raw.

Original

Box::from_raw

Safety

This function is unsafe because improper use may lead to memory problems. For example, a double-free may occur if the function is called twice on the same raw bit-slice pointer.

Examples

Recreate a BitBox which was previously converted to a raw bit-slice pointer using BitBox::into_raw:

use bitvec::prelude::*;

let x = bitbox![0; 10];
let ptr = BitBox::into_raw(x);
let x = unsafe { BitBox::from_raw(ptr) };

pub fn into_raw(this: Self) -> *mut BitSlice<O, T>

Consumes the BitBox, returning a raw bit-slice pointer.

The bit-slice pointer will be properly encoded and non-null.

After calling this function, the caller is responsible for the memory previously managed by the BitBox. In particular, the caller should properly release the memory by converting the bit-slice pointer back into a BitBox with the from_raw function, allowing the BitBox destructor to perform the cleanup.

Note: this is an associated function, which means that you have to call it as BitBox::into_raw(b) instead of b.into_raw(). This is to match signatures with the standard library’s Box API; there will never be a name conflict with BitSlice.

Original

Box::into_raw

Examples

Converting the raw bit-slice pointer back into a BitBox with BitBox::from_raw for automatic cleanup:

use bitvec::prelude::*;

let x = bitbox![0; 50];
let p = BitBox::into_raw(x);
let x = unsafe { BitBox::from_raw(p) };

You may not deällocate pointers produced by this function through any other manner.

pub fn leak<'a>(this: Self) -> &'a mut BitSlice<O, T> where
    T: 'a, 

Consumes and leaks the BitBox, returning a mutable reference, &'a mut BitSlice<O, T>. This is eligible to be promoted to the 'static lifetime.

Original

Box::leak

This function is mainly useful for data that lives for the remainder of the program’s life. Dropping the returned reference will cause a memory leak. If this is not acceptable, the reference should first be wrapped with the BitBox::from_raw function producing a BitBox. This BitBox can then be dropped which will properly deällocate the memory.

Note: this is an associated function, which means that you have to call it as BitBox::leak(b) instead of b.leak(). This is to match signatures with the standard library’s Box API; there will never be a name conflict with BitSlice.

Original

Box::leak

Examples

Simple usage:

use bitvec::prelude::*;

let b = bitbox![0; 50];
let static_ref: &'static mut BitSlice = BitBox::leak(b);
static_ref.set(0, true);
assert!(static_ref[0]);

impl<O, T> BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

General-purpose functions not present on Box<[T]>.

pub fn from_bitslice(slice: &BitSlice<O, T>) -> Self

Copies a BitSlice region into a new BitBox allocation.

Effects

This delegates to BitVec::from_bitslice, then discards the excess capacity.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 1, 1, 0, 1, 1];
let bb = BitBox::from_bitslice(&bits[2 ..]);
assert_eq!(bb, bits[2 ..]);
assert_eq!(bb.as_slice(), bits.as_slice());

pub fn from_boxed_slice(boxed: Box<[T]>) -> Self

Converts a Box<[T]> into a BitBox<O, T>` without copying its buffer.

Parameters

• boxed: A boxed slice to view as bits.

Returns

A BitBox over the boxed buffer.

Panics

This panics if boxed is too long to convert into a BitBox. See BitSlice::MAX_ELTS.

Examples

use bitvec::prelude::*;

let boxed: Box<[u8]> = Box::new([0; 4]);
let addr = boxed.as_ptr();
let bb = BitBox::<LocalBits, _>::from_boxed_slice(boxed);
assert_eq!(bb, bits![0; 32]);
assert_eq!(addr, bb.as_slice().as_ptr());

pub fn try_from_boxed_slice(boxed: Box<[T]>) -> Result<Self, Box<[T]>>

Converts a Box<[T]> into a BitBox<O, T> without copying its buffer.

This method takes ownership of a memory buffer and enables it to be used as a bit-box. Because Box<[T]> can be longer than BitBoxes, this is a fallible method, and the original box will be returned if it cannot be converted.

Parameters

• boxed: Some boxed slice of memory, to be viewed as bits.

Returns

If boxed is short enough to be viewed as a BitBox, then this returns a BitBox over the boxed buffer. If boxed is too long, then this returns boxed unmodified.

Examples

use bitvec::prelude::*;

let boxed: Box<[u8]> = Box::new([0; 4]);
let addr = boxed.as_ptr();
let bb = BitBox::<LocalBits, _>::try_from_boxed_slice(boxed).unwrap();
assert_eq!(bb[..], bits![0; 32]);
assert_eq!(addr, bb.as_slice().as_ptr());

pub fn into_boxed_slice(self) -> Box<[T]>

Converts the slice back into an ordinary slice of memory elements.

This does not affect the slice’s buffer, only the handle used to control it.

Parameters

• self

Returns

An ordinary boxed slice containing all of the bit-slice’s memory buffer.

Examples

use bitvec::prelude::*;

let bb = bitbox![0; 5];
let addr = bb.as_slice().as_ptr();
let boxed = bb.into_boxed_slice();
assert_eq!(boxed[..], [0][..]);
assert_eq!(addr, boxed.as_ptr());

pub fn into_bitvec(self) -> BitVec<O, T>

Converts self into a vector without clones or allocation.

The resulting vector can be converted back into a box via BitVec<O, T>’s .into_boxed_bitslice() method.

Original

slice::into_vec

API Differences

Despite taking a Box<[T]> receiver, this function is written in an impl<T> [T] block.

Rust does not allow the text

impl<O, T> BitSlice<O, T> {
  fn into_bitvec(self: BitBox<O, T>);
}

to be written, and BitBox exists specifically because Box<BitSlice<>> cannot be written either, so this function must be implemented directly on BitBox rather than on BitSlice with a boxed receiver.

Examples

use bitvec::prelude::*;

let bb = bitbox![0, 1, 0, 1];
let bv = bb.into_bitvec();

assert_eq!(bv, bitvec![0, 1, 0, 1]);

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

Views the buffer’s contents as a BitSlice.

This is equivalent to &bb[..].

Examples

use bitvec::prelude::*;

let bb = bitbox![0, 1, 1, 0];
let bits = bb.as_bitslice();

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

Extracts a mutable bit-slice of the entire vector.

Equivalent to &mut bv[..].

Examples

use bitvec::prelude::*;

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

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

Extracts an element slice containing the entire box.

Analogue

See .as_bitslice() for a &BitBox -> &BitSlice transform.

Examples

use bitvec::prelude::*;
use std::io::{self, Write};
let buffer = bitbox![Msb0, u8; 0, 1, 0, 1, 1, 0, 0, 0];
io::sink().write(buffer.as_slice()).unwrap();

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

Extracts a mutable slice of the entire box.

Analogue

See .as_mut_bitslice() for a &mut BitBox -> &mut BitSlice transform.

Examples

use bitvec::prelude::*;
use std::io::{self, Read};
let mut buffer = bitbox![Msb0, u8; 0; 24];
io::repeat(0b101).read_exact(buffer.as_mut_slice()).unwrap();

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

Sets the uninitialized bits of the vector to a fixed value.

This method modifies all bits in the allocated buffer that are outside the self.as_bitslice() view so that they have a consistent value. This can be used to zero the uninitialized memory so that when viewed as a raw memory slice, bits outside the live region have a predictable value.

Examples

use bitvec::prelude::*;

let mut bb = BitBox::new(&220u8.view_bits::<Lsb0>()[.. 4]);
assert_eq!(bb.count_ones(), 2);
assert_eq!(bb.as_slice(), &[220u8]);

bb.set_uninitialized(false);
assert_eq!(bb.as_slice(), &[12u8]);

bb.set_uninitialized(true);
assert_eq!(bb.as_slice(), &[!3u8]);

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

pub fn len(&self) -> usize

Returns the number of bits in the slice.

Original

slice::len

Examples

use bitvec::prelude::*;

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

pub fn is_empty(&self) -> bool

Returns true if the slice has a length of 0.

Original

slice::is_empty

Examples

use bitvec::prelude::*;

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

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

Returns the first bit of the slice, or None if it is empty.

Original

Examples

use bitvec::prelude::*;

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

let w = bits![];
assert_eq!(None, w.first());

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

Returns a mutable pointer to the first bit of the slice, or None if it is empty.

Original

slice::first_mut

API Differences

This crate cannot manifest &mut bool references, and must use the BitRef proxy type where &mut bool exists in the standard library API. The proxy value must be bound as mut in order to write through it.

Examples

use bitvec::prelude::*;

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

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

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

Returns the first and all the rest of the bits of the slice, or None if it is empty.

Original

slice::split_first

Examples

use bitvec::prelude::*;

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

if let Some((first, rest)) = x.split_first() {
  assert_eq!(first, &true);
  assert_eq!(rest, bits![0; 2]);
}

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

Returns the first and all the rest of the bits of the slice, or None if it is empty.

Original

slice::split_first_mut

API Differences

This crate cannot manifest &mut bool references, and must use the BitRef proxy type where &mut bool exists in the standard library API. The proxy value must be bound as mut in order to write through it.

Because the references are permitted to use the same memory address, they are marked as aliasing in order to satisfy Rust’s requirements about freedom from data races.

Examples

use bitvec::prelude::*;

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

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

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

Returns the last and all the rest of the bits of the slice, or None if it is empty.

Original

slice::split_last

Examples

use bitvec::prelude::*;

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

if let Some((last, rest)) = x.split_last() {
  assert_eq!(last, &true);
  assert_eq!(rest, bits![0; 2]);
}

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

Returns the last and all the rest of the bits of the slice, or None if it is empty.

Original

slice::split_last_mut

API Differences

This crate cannot manifest &mut bool references, and must use the BitRef proxy type where &mut bool exists in the standard library API. The proxy value must be bound as mut in order to write through it.

Because the references are permitted to use the same memory address, they are marked as aliasing in order to satisfy Rust’s requirements about freedom from data races.

Examples

use bitvec::prelude::*;

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

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

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

Returns the last bit of the slice, or None if it is empty.

Original

slice::last

Examples

use bitvec::prelude::*;

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

let w = bits![];
assert_eq!(None, w.last());

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

Returns a mutable pointer to the last bit in the slice.

Original

slice::last_mut

API Differences

This crate cannot manifest &mut bool references, and must use the BitRef proxy type where &mut bool exists in the standard library API. The proxy value must be bound as mut in order to write through it.

Examples

use bitvec::prelude::*;

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

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

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

Returns a reference to a bit or subslice depending on the type of index.

• If given a position, returns a reference to the bit at that position or None if out of bounds.
• If given a range, returns the subslice corresponding to that range, or None if out of bounds.

Original

slice::get

Examples

use bitvec::prelude::*;

let v = bits![0, 1, 0];
assert_eq!(Some(&true), v.get(1).as_deref());
assert_eq!(Some(bits![0, 1]), v.get(0 .. 2));
assert_eq!(None, v.get(3));
assert_eq!(None, v.get(0 .. 4));

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

Returns a mutable reference to a bit or subslice depending on the type of index (see .get()) or None if the index is out of bounds.

Original

slice::get_mut

API Differences

This crate cannot manifest &mut bool references, and must use the BitRef proxy type where &mut bool exists in the standard library API. The proxy value must be bound as mut in order to write through it.

Examples

use bitvec::prelude::*;

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

if let Some(mut bit) = x.get_mut(1) {
  *bit = true;
}
assert_eq!(x, bits![0, 1, 1]);

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

Returns a reference to a bit or subslice, without doing bounds checking.

This is generally not recommended; use with caution! Calling this method with an out-of-bounds index is undefined behavior even if the resulting reference is not used. For a safe alternative, see .get().

Original

slice::get_unchecked

Examples

use bitvec::prelude::*;

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

unsafe {
  assert_eq!(x.get_unchecked(1), &true);
}

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

Returns a mutable reference to a bit or subslice, without doing bounds checking.

This is generally not recommended; use with caution! Calling this method with an out-of-bounds index is undefined behavior even if the resulting reference is not used. For a safe alternative, see [.get_mut()].

Original

slice::get_unchecked_mut

API Differences

This crate cannot manifest &mut bool references, and must use the BitRef proxy type where &mut bool exists in the standard library API. The proxy value must be bound as mut in order to write through it.

Examples

use bitvec::prelude::*;

let x = bits![mut 0; 3];
unsafe {
  let mut bit = x.get_unchecked_mut(1);
  *bit = true;
}
assert_eq!(x, bits![0, 1, 0]);

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

Swaps two bits in the slice.

Original

slice::swap

Arguments

• a: The index of the first bit
• b: The index of the second bit

Panics

Panics if a or b are out of bounds.

Examples

use bitvec::prelude::*;

let v = bits![mut 0, 1, 1, 0];
v.swap(1, 3);
assert_eq!(v, bits![0, 0, 1, 1]);

pub fn reverse(&mut self)

Reverses the order of bits in the slice, in place.

Original

slice::reverse

Examples

use bitvec::prelude::*;

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

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

Returns an iterator over the slice.

Original

slice::iter

API Differences

This iterator yields BitRef proxy references, rather than &bool ordinary references. It does so in order to promote consistency in the crate, and make switching between immutable and mutable single-bit access easier.

The produced iterator has a by_ref adapter that yields &bool references, and a by_val adapter that yields bool values. Use these methods to fit this iterator into APIs that expect ordinary bool inputs.

Examples

use bitvec::prelude::*;

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

assert_eq!(iterator.next().as_deref(), Some(&false));
assert_eq!(iterator.next().as_deref(), Some(&false));
assert_eq!(iterator.next().as_deref(), Some(&true));
assert_eq!(iterator.next().as_deref(), None);

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

Returns an iterator that allows modifying each bit.

Original

slice::iter_mut

API Differences

This crate cannot manifest &mut bool references, and must use the BitRef proxy type where &mut bool exists in the standard library API. The proxy value must be bound as mut in order to write through it.

This iterator marks each yielded item as aliased, as iterators can be used to yield multiple items into the same scope. If you are using the iterator in a manner that ensures that all yielded items have disjoint lifetimes, you can use the .remove_alias() adapter on it to remove the alias marker from the yielded subslices.

Examples

use bitvec::prelude::*;

let x = bits![mut 0, 0, 1];
for mut bit in x.iter_mut() {
  *bit = !*bit;
}
assert_eq!(x, bits![1, 1, 0]);

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

Returns an iterator over all contiguous windows of length size. The windows overlap. If the slice is shorter than size, the iterator returns no values.

Original

slice::windows

Panics

Panics if size is 0.

Examples

use bitvec::prelude::*;

let slice = bits![0, 0, 1, 1];
let mut iter = slice.windows(2);
assert_eq!(iter.next().unwrap(), bits![0; 2]);
assert_eq!(iter.next().unwrap(), bits![0, 1]);
assert_eq!(iter.next().unwrap(), bits![1; 2]);
assert!(iter.next().is_none());

If the slice is shorter than size:

use bitvec::prelude::*;

let slice = bits![0; 3];
let mut iter = slice.windows(4);
assert!(iter.next().is_none());

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

Returns an iterator over chunk_size bits of the slice at a time, starting at the beginning of the slice.

The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

See .chunks_exact() for a variant of this iterator that returns chunks of always exactly chunk_size bits, and .rchunks() for the same iterator but starting at the end of the slice.

Original

slice::chunks

Panics

Panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let slice = bits![0, 1, 0, 0, 1];
let mut iter = slice.chunks(2);
assert_eq!(iter.next().unwrap(), bits![0, 1]);
assert_eq!(iter.next().unwrap(), bits![0, 0]);
assert_eq!(iter.next().unwrap(), bits![1]);
assert!(iter.next().is_none());

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

Returns an iterator over chunk_size bits of the slice at a time, starting at the beginning of the slice.

The chunks are mutable slices, and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

See .chunks_exact_mut() for a variant of this iterator that returns chunks of always exactly chunk_size bits, and .rchunks_mut() for the same iterator but starting at the end of the slice.

Original

slice::chunks_mut

API Differences

This iterator marks each yielded item as aliased, as iterators can be used to yield multiple items into the same scope. If you are using the iterator in a manner that ensures that all yielded items have disjoint lifetimes, you can use the .remove_alias() adapter on it to remove the alias marker from the yielded subslices.

Panics

Panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let v = bits![mut 0; 5];
let mut count = 1;

for chunk in v.chunks_mut(2) {
  for mut bit in chunk.iter_mut() {
    *bit = count % 2 == 0;
  }
  count += 1;
}
assert_eq!(v, bits![0, 0, 1, 1, 0]);

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

Returns an iterator over chunk_size bits of the slice at a time, starting at the beginning of the slice.

The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last up to chunk_size-1 bits will be omitted and can be retrieved from the .remainder() method of the iterator.

Due to each chunk having exactly chunk_size bits, the compiler may be able to optimize the resulting code better than in the case of .chunks().

See .chunks() for a variant of this iterator that also returns the remainder as a smaller chunk, and .rchunks_exact() for the same iterator but starting at the end of the slice.

Original

slice::chunks_exact

Panics

Panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let slice = bits![0, 1, 1, 0, 0];
let mut iter = slice.chunks_exact(2);
assert_eq!(iter.next().unwrap(), bits![0, 1]);
assert_eq!(iter.next().unwrap(), bits![1, 0]);
assert!(iter.next().is_none());
assert_eq!(iter.remainder(), bits![0]);

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

Returns an iterator over chunk_size bits of the slice at a time, starting at the beginning of the slice.

The chunks are mutable slices, and do not overlap. If chunk_size does not divide the length of the slice, then the last up to chunk_size-1 bits will be omitted and can be retrieved from the .into_remainder() method of the iterator.

Due to each chunk having exactly chunk_size bits, the compiler may be able to optimize the resulting code better than in the case of .chunks_mut().

See .chunks_mut() for a variant of this iterator that also returns the remainder as a smaller chunk, and .rchunks_exact_mut() for the same iterator but starting at the end of the slice.

Original

slice::chunks_exact_mut

API Differences

This iterator marks each yielded item as aliased, as iterators can be used to yield multiple items into the same scope. If you are using the iterator in a manner that ensures that all yielded items have disjoint lifetimes, you can use the .remove_alias() adapter on it to remove the alias marker from the yielded subslices.

Panics

Panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let v = bits![mut 0; 5];

for chunk in v.chunks_exact_mut(2) {
  chunk.set_all(true);
}
assert_eq!(v, bits![1, 1, 1, 1, 0]);

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

Returns an iterator over chunk_size bits of the slice at a time, starting at the end of the slice.

The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

See .rchunks_exact() for a variant of this iterator that returns chunks of always exactly chunk_size bits, and .chunks() for the same iterator but starting at the beginning of the slice.

Original

slice::rchunks

Panics

Panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let slice = bits![0, 1, 0, 0, 1];
let mut iter = slice.rchunks(2);
assert_eq!(iter.next().unwrap(), bits![0, 1]);
assert_eq!(iter.next().unwrap(), bits![1, 0]);
assert_eq!(iter.next().unwrap(), bits![0]);
assert!(iter.next().is_none());

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

Returns an iterator over chunk_size bits of the slice at a time, starting at the end of the slice.

The chunks are mutable slices, and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

See .rchunks_exact_mut() for a variant of this iterator that returns chunks of always exactly chunk_size bits, and .chunks_mut() for the same iterator but starting at the beginning of the slice.

Original

slice::rchunks_mut

API Differences

This iterator marks each yielded item as aliased, as iterators can be used to yield multiple items into the same scope. If you are using the iterator in a manner that ensures that all yielded items have disjoint lifetimes, you can use the .remove_alias() adapter on it to remove the alias marker from the yielded subslices.

Panics

Panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let v = bits![mut 0; 5];
let mut count = 1;

for chunk in v.rchunks_mut(2) {
  for mut bit in chunk.iter_mut() {
    *bit = count % 2 == 0;
  }
  count += 1;
}
assert_eq!(v, bits![0, 1, 1, 0, 0]);

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

Returns an iterator over chunk_size bits of the slice at a time, starting at the end of the slice.

The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last up to chunk_size-1 bits will be omitted and can be retrieved from the .remainder() method of the iterator.

Due to each chunk having exactly chunk_size bits, the compiler may be able to optimize the resulting code better than in the case of .rchunks().

See .rchunks() for a variant of this iterator that also returns the remainder as a smaller chunk, and .chunks_exact() for the same iterator but starting at the beginning of the slice.

Original

slice::rchunks_exact

Panics

Panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let slice = bits![0, 0, 1, 1, 0];
let mut iter = slice.rchunks_exact(2);
assert_eq!(iter.next().unwrap(), bits![1, 0]);
assert_eq!(iter.next().unwrap(), bits![0, 1]);
assert!(iter.next().is_none());
assert_eq!(iter.remainder(), bits![0]);

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

Returns an iterator over chunk_size bits of the slice at a time, starting at the end of the slice.

The chunks are mutable slices, and do not overlap. If chunk_size does not divide the length of the slice, then the last up to chunk_size-1 bits will be omitted and can be retrieved from the .into_remainder() method of the iterator.

Due to each chunk having exactly chunk_size bits, the compiler may be able to optimize the resulting code better than in the case of .rchunks_mut().

See .rchunks_mut() for a variant of this iterator that also returns the remainder as a smaller chunk, and .chunks_exact_mut() for the same iterator but starting at the beginning of the slice.

Original

slice::rchunks_exact_mut

API Differences

This iterator marks each yielded item as aliased, as iterators can be used to yield multiple items into the same scope. If you are using the iterator in a manner that ensures that all yielded items have disjoint lifetimes, you can use the .remove_alias() adapter on it to remove the alias marker from the yielded subslices.

Panics

Panics if chunk_size is 0.

Examples

use bitvec::prelude::*;

let v = bits![mut 0; 5];

for chunk in v.rchunks_exact_mut(2) {
  chunk.set_all(true);
}
assert_eq!(v, bits![0, 1, 1, 1, 1]);

pub fn split_at(&self, mid: usize) -> (&Self, &Self)

Divides one slice into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Original

slice::split_at

Panics

Panics if mid > len.

Behavior

When mid is 0 or self.len(), then the left or right return values, respectively, are empty slices. Empty slice references produced by this method are specified to have the address information you would expect: a left empty slice has the same base address and start bit as self, and a right empty slice will have its address raised by self.len().

Examples

use bitvec::prelude::*;

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

{
  let (left, right) = v.split_at(0);
  assert_eq!(left, bits![]);
  assert_eq!(right, v);
}

{
  let (left, right) = v.split_at(2);
  assert_eq!(left, bits![0, 0]);
  assert_eq!(right, bits![0, 1, 1, 1]);
}

{
  let (left, right) = v.split_at(6);
  assert_eq!(left, v);
  assert_eq!(right, bits![]);
}

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

Divides one mutable slice into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Original

slice::split_at_mut

API Differences

The partition index mid may occur anywhere in the slice, and as a result the two returned slices may both have write access to the memory address containing mid. As such, the returned slices must be marked with T::Alias in order to correctly manage memory access going forward.

This marking is applied to all memory accesses in both slices, regardless of whether any future accesses actually require it. To limit the alias marking to only the addresses that need it, use [.bit_domain()] or [.bit_domain_mut()] to split either slice into its aliased and unaliased subslices.

Panics

Panics if mid > len.

Behavior

When mid is 0 or self.len(), then the left or right return values, respectively, are empty slices. Empty slice references produced by this method are specified to have the address information you would expect: a left empty slice has the same base address and start bit as self, and a right empty slice will have its address raised by self.len().

Examples

use bitvec::prelude::*;

let v = bits![mut 0, 0, 0, 1, 1, 1];
// scoped to restrict the lifetime of the borrows
{
  let (left, right) = v.split_at_mut(2);
  assert_eq!(left, bits![0, 0]);
  assert_eq!(right, bits![0, 1, 1, 1]);

  left.set(1, true);
  right.set(1, false);
}
assert_eq!(v, bits![0, 1, 0, 0, 1, 1]);

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

Returns an iterator over subslices separated by bits that match pred. The matched bit is not contained in the subslices.

Original

slice::split

API Differences

In order to allow more than one bit of information for the split decision, the predicate receives the index of each bit, as well as its value.

Examples

use bitvec::prelude::*;

let slice = bits![0, 1, 1, 0];
let mut iter = slice.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, an empty slice will be the first item returned by the iterator. Similarly, if the last bit in the slice is matched, an empty slice will be the last item returned by the iterator:

use bitvec::prelude::*;

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

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

If two matched bits are directly adjacent, an empty slice will be present between them:

use bitvec::prelude::*;

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

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

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

Returns an iterator over mutable subslices separated by bits that match pred. The matched bit is not contained in the subslices.

Original

slice::split_mut

API Differences

In order to allow more than one bit of information for the split decision, the predicate receives the index of each bit, as well as its value.

This iterator marks each yielded item as aliased, as iterators can be used to yield multiple items into the same scope. If you are using the iterator in a manner that ensures that all yielded items have disjoint lifetimes, you can use the .remove_alias() adapter on it to remove the alias marker from the yielded subslices.

Examples

use bitvec::prelude::*;

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

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

Returns an iterator over subslices separated by bits that match pred, starting at the end of the slice and working backwards. The matched bit is not contained in the subslices.

Original

slice::rsplit

API Differences

In order to allow more than one bit of information for the split decision, the predicate receives the index of each bit, as well as its value.

Examples

use bitvec::prelude::*;

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

assert_eq!(iter.next().unwrap(), bits![1; 2]);
assert_eq!(iter.next().unwrap(), bits![1; 3]);
assert!(iter.next().is_none());

As with .split(), if the first or last bit is matched, an empty slice will be the first (or last) item returned by the iterator.

use bitvec::prelude::*;

let v = bits![1, 0, 0, 1, 0, 0, 1];
let mut it = v.rsplit(|_pos, bit| *bit);
assert_eq!(it.next().unwrap(), bits![]);
assert_eq!(it.next().unwrap(), bits![0; 2]);
assert_eq!(it.next().unwrap(), bits![0; 2]);
assert_eq!(it.next().unwrap(), bits![]);
assert!(it.next().is_none());

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

Returns an iterator over mutable subslices separated by bits that match pred, starting at the end of the slice and working backwards. The matched bit is not contained in the subslices.

Original

slice::rsplit_mut

API Differences

In order to allow more than one bit of information for the split decision, the predicate receives the index of each bit, as well as its value.

This iterator marks each yielded item as aliased, as iterators can be used to yield multiple items into the same scope. If you are using the iterator in a manner that ensures that all yielded items have disjoint lifetimes, you can use the .remove_alias() adapter on it to remove the alias marker from the yielded subslices.

Examples

use bitvec::prelude::*;

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

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

Returns an iterator over subslices separated by bits that match pred, limited to returning at most n items. The matched bit is not contained in the subslices.

The last item returned, if any, will contain the remainder of the slice.

Original

slice::splitn

API Differences

In order to allow more than one bit of information for the split decision, the predicate receives the index of each bit, as well as its value.

Examples

Print the slice split once by set bits (i.e., [0, 0,], [0, 1, 0]):

use bitvec::prelude::*;

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

for group in v.splitn(2, |_pos, bit| *bit) {
  println!("{:b}", group);
}

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

Returns an iterator over subslices separated by bits that match pred, limited to returning at most n items. The matched bit is not contained in the subslices.

The last item returned, if any, will contain the remainder of the slice.

Original

slice::splitn_mut

API Differences

In order to allow more than one bit of information for the split decision, the predicate receives the index of each bit, as well as its value.

This iterator marks each yielded item as aliased, as iterators can be used to yield multiple items into the same scope. If you are using the iterator in a manner that ensures that all yielded items have disjoint lifetimes, you can use the .remove_alias() adapter on it to remove the alias marker from the yielded subslices.

Examples

use bitvec::prelude::*;

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

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

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

Returns an iterator over subslices separated by bits that match pred, limited to returning at most n items. This starts at the end of the slice and works backwards. The matched bit is not contained in the subslices.

The last item returned, if any, will contain the remainder of the slice.

Original

slice::rsplitn

API Differences

In order to allow more than one bit of information for the split decision, the predicate receives the index of each bit, as well as its value.

Examples

Print the slice split once, starting from the end, by set bits (i.e., [0], [0, 0, 1, 0]):

use bitvec::prelude::*;

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

for group in v.rsplitn(2, |_pos, bit| *bit) {
  println!("{:b}", group);
}

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

Returns an iterator over subslices separated by bits that match pred, limited to returning at most n items. This starts at the end of the slice and works backwards. The matched bit is not contained in the subslices.

The last item returned, if any, will contain the remainder of the slice.

Original

slice::rsplitn_mut

API Differences

In order to allow more than one bit of information for the split decision, the predicate receives the index of each bit, as well as its value.

This iterator marks each yielded item as aliased, as iterators can be used to yield multiple items into the same scope. If you are using the iterator in a manner that ensures that all yielded items have disjoint lifetimes, you can use the .remove_alias() adapter on it to remove the alias marker from the yielded subslices.

Examples

use bitvec::prelude::*;

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

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

pub fn contains<O2, T2>(&self, x: &BitSlice<O2, T2>) -> bool where
    O2: BitOrder,
    T2: BitStore, 

Returns true if the slice contains a subslice that matches the given span.

Original

slice::contains

API Differences

This searches for a matching subslice (allowing different type parameters) rather than for a specific bit. Searching for a contained element with a given value is not as useful on a collection of bool.

Furthermore, BitSlice defines any and not_all, which are optimized searchers for any true or false bit, respectively, in a sequence.

Examples

use bitvec::prelude::*;

let data = 0b0101_1010u8;
let bits_msb = data.view_bits::<Msb0>();
let bits_lsb = data.view_bits::<Lsb0>();
assert!(bits_msb.contains(&bits_lsb[1 .. 5]));

This example uses a palindrome pattern to demonstrate that the slice being searched for does not need to have the same type parameters as the slice being searched.

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

Returns true if needle is a prefix of the slice.

Original

slice::starts_with

Examples

use bitvec::prelude::*;

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

Always returns true if needle is an empty slice:

use bitvec::prelude::*;

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

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

Returns true if needle is a suffix of the slice.

Original

slice::ends_with

Examples

use bitvec::prelude::*;

let v = bits![0, 1, 0, 0];
assert!(v.ends_with(bits![0]));
assert!(v.ends_with(bits![0; 2]));
assert!(!v.ends_with(bits![1]));
assert!(!v.ends_with(bits![1, 0]));

Always returns true if needle is an empty slice:

use bitvec::prelude::*;

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

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

Rotates the slice in-place such that the first by bits of the slice move to the end while the last self.len() - by bits move to the front. After calling .rotate_left(), the bit previously at index by will become the first bit in the slice.

Original

slice::rotate_left

Panics

This function will panic if by is greater than the length of the slice. Note that by == self.len() does not panic and is a noöp.

Complexity

Takes linear (in self.len()) time.

Examples

use bitvec::prelude::*;

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

Rotating a subslice:

use bitvec::prelude::*;

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

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

Rotates the slice in-place such that the first self.len() - by bits of the slice move to the end while the last by bits move to the front. After calling .rotate_right(), the bit previously at index `self.len()

• by` will become the first bit in the slice.

Original

slice::rotate_right

Panics

This function will panic if by is greater than the length of the slice. Note that by == self.len() does not panic and is a noöp.

Complexity

Takes linear (in self.len()) time.

Examples

use bitvec::prelude::*;

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

Rotating a subslice:

use bitvec::prelude::*;

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

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

Copies bits from one part of the slice to another part of itself.

src is the range within self to copy from. dest is the starting index of the range within self to copy to, which will have the same length as src. The two ranges may overlap. The ends of the two ranges must be less than or equal to self.len().

Original

slice::copy_within

Panics

This function will panic if either range exceeds the end of the slice, or if the end of src is before the start.

Examples

Copying four bits within a slice:

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);

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

pub unsafe fn align_to<U>(&self) -> (&Self, &BitSlice<O, U>, &Self) where
    U: BitStore, 

Transmute the bit-slice to a bit-slice of another type, ensuring alignment of the types is maintained.

Original

slice::align_to

API Differences

Type U is required to have the same BitStore type family as type T. If T is a fundamental integer, so must U be; if T is an ::Alias type, then so must U. Changing the type family with this method is unsound and strictly forbidden. Unfortunately, this cannot be encoded in the type system, so you are required to abide by this limitation yourself.

Implementation

The algorithm used to implement this function attempts to create the widest possible span for the middle slice. However, the slice divisions must abide by the Domain restrictions: the left and right slices produced by this function will include the head and tail elements of the domain (if present), as well as the left and right subslices (if any) produced by calling slice::align_to on the domain body (if present).

The standard library implementation currently maximizes the width of the center slice, but its API does not guarantee this property, and retains the right to produce pessimal slices. As such, this function cannot guarantee maximal center slice width either, and you cannot rely on this behavior for correctness of your work; it is only a possible performance improvement.

Safety

This method is essentially a mem::transmute with respect to the memory region in the retured middle slice, so all of the usual caveats pertaining to mem::transmute::<T, U> also apply here.

Examples

Basic usage:

use bitvec::prelude::*;

unsafe {
  let bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
  let bits = bytes.view_bits::<LocalBits>();
  let (prefix, shorts, suffix) = bits.align_to::<u16>();
  match prefix.len() {
    0 => {
      assert_eq!(shorts, bits[.. 48]);
      assert_eq!(suffix, bits[48 ..]);
    },
    8 => {
      assert_eq!(prefix, bits[.. 8]);
      assert_eq!(shorts, bits[8 ..]);
    },
    _ => unreachable!("This case will not occur")
  }
}

pub unsafe fn align_to_mut<U>(
    &mut self
) -> (&mut Self, &mut BitSlice<O, U>, &mut Self) where
    U: BitStore, 

Transmute the bit-slice to a bit-slice of another type, ensuring alignment of the types is maintained.

Original

slice::align_to_mut

API Differences

Type U is required to have the same BitStore type family as type T. If T is a fundamental integer, so must U be; if T is an ::Alias type, then so must U. Changing the type family with this method is unsound and strictly forbidden. Unfortunately, this cannot be encoded in the type system, so you are required to abide by this limitation yourself.

Implementation

The algorithm used to implement this function attempts to create the widest possible span for the middle slice. However, the slice divisions must abide by the DomainMut restrictions: the left and right slices produced by this function will include the head and tail elements of the domain (if present), as well as the left and right subslices (if any) produced by calling slice::align_to_mut on the domain body (if present).

The standard library implementation currently maximizes the width of the center slice, but its API does not guarantee this property, and retains the right to produce pessimal slices. As such, this function cannot guarantee maximal center slice width either, and you cannot rely on this behavior for correctness of your work; it is only a possible performance improvement.

Safety

This method is essentially a mem::transmute with respect to the memory region in the retured middle slice, so all of the usual caveats pertaining to mem::transmute::<T, U> also apply here.

Examples

Basic usage:

use bitvec::prelude::*;

unsafe {
  let mut bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
  let bits = bytes.view_bits_mut::<LocalBits>();
  let (prefix, shorts, suffix) = bits.align_to_mut::<u16>();
  //  same access and behavior as in `align_to`
}

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

Creates a vector by repeating a slice n times.

Original

slice::repeat

Panics

This function will panic if the capacity would overflow.

Examples

Basic usage:

use bitvec::prelude::*;

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

A panic upon overflow:

use bitvec::prelude::*;

// this will panic at runtime
bits![0, 1].repeat(BitSlice::<LocalBits, usize>::MAX_BITS);

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

Writes a new bit at a given index.

Parameters

• &mut self
• index: The bit index at which to write. It must be in the range 0 .. self.len().
• value: The value to be written; true for 1 or false for 0.

Effects

If index is valid, then the bit to which it refers is set to value.

Panics

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

Examples

use bitvec::prelude::*;

let bits = bits![mut 0];

assert!(!bits[0]);
bits.set(0, true);
assert!(bits[0]);

This example panics when it attempts to set a bit that is out of bounds.

use bitvec::prelude::*;

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

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

Writes a new bit at a given index.

This method supports writing through a shared reference to a bit that may be observed by other BitSlice handles. It is only present when the T type parameter supports such shared mutation (measured by the Radium trait).

Parameters

• &self
• index: The bit index at which to write. It must be in the range 0 .. self.len().
• value: The value to be written; true for 1 or false for 0.

Effects

If index is valid, then the bit to which it refers is set to value. If T is an atomic, this will lock the memory bus for the referent address, and may cause stalls.

Panics

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

Examples

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

let byte = Cell::new(0u8);
let bits = byte.view_bits::<Msb0>();
let bits_2 = bits;

bits.set_aliased(1, true);
assert!(bits_2[1]);

This example panics when it attempts to set a bit that is out of bounds.

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

let byte = Cell::new(0u8);
let bits = byte.view_bits::<Lsb0>();
bits.set_aliased(8, false);

pub fn any(&self) -> bool

Tests if any bit in the slice is set (logical ∨).

Truth Table

0 0 => 0
0 1 => 1
1 0 => 1
1 1 => 1

Parameters

• &self

Returns

Whether any bit in the slice domain is set. The empty slice returns false.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0];
assert!(bits[.. 2].any());
assert!(!bits[2 ..].any());

pub fn all(&self) -> bool

Tests if all bits in the slice domain are set (logical ∧).

Truth Table

0 0 => 0
0 1 => 0
1 0 => 0
1 1 => 1

Parameters

• &self

Returns

Whether all bits in the slice domain are set. The empty slice returns true.

Examples

use bitvec::prelude::*;

let bits = bits![1, 1, 0, 1];
assert!(bits[.. 2].all());
assert!(!bits[2 ..].all());

pub fn not_any(&self) -> bool

Tests if all bits in the slice are unset (logical ¬∨).

Truth Table

0 0 => 1
0 1 => 0
1 0 => 0
1 1 => 0

Parameters

• &self

Returns

Whether all bits in the slice domain are unset.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0];
assert!(!bits[.. 2].not_any());
assert!(bits[2 ..].not_any());

pub fn not_all(&self) -> bool

Tests if any bit in the slice is unset (logical ¬∧).

Truth Table

0 0 => 1
0 1 => 1
1 0 => 1
1 1 => 0

Parameters

• &self

Returns

Whether any bit in the slice domain is unset.

Examples

use bitvec::prelude::*;

let bits = bits![1, 1, 0, 1];
assert!(!bits[.. 2].not_all());
assert!(bits[2 ..].not_all());

pub fn some(&self) -> bool

Tests whether the slice has some, but not all, bits set and some, but not all, bits unset.

This is false if either .all() or .not_any() are true.

Truth Table

0 0 => 0
0 1 => 1
1 0 => 1
1 1 => 0

Parameters

• &self

Returns

Whether the slice domain has mixed content. The empty slice returns false.

Examples

use bitvec::prelude::*;

let data = 0b111_000_10u8;
let bits = bits![1, 1, 0, 0, 1, 0];

assert!(!bits[.. 2].some());
assert!(!bits[2 .. 4].some());
assert!(bits.some());

pub fn count_ones(&self) -> usize

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

Parameters

• &self

Returns

The number of bits in the slice domain that are set to 1.

Examples

Basic usage:

use bitvec::prelude::*;

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

pub fn count_zeros(&self) -> usize

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

Parameters

• &self

Returns

The number of bits in the slice domain that are cleared to 0.

Examples

Basic usage:

use bitvec::prelude::*;

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

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

Enumerates all bits in a BitSlice that are set to 1.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1, 0, 0, 0, 1];
let mut indices = [1, 4, 8].iter().copied();

let mut iter_ones = bits.iter_ones();
let mut compose = bits.iter()
  .copied()
  .enumerate()
  .filter_map(|(idx, bit)| if bit { Some(idx) } else { None });

for ((a, b), c) in iter_ones.zip(compose).zip(indices) {
  assert_eq!(a, b);
  assert_eq!(b, c);
}

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

Enumerates all bits in a BitSlice that are cleared to 0.

Examples

use bitvec::prelude::*;

let bits = bits![1, 0, 1, 1, 0, 1, 1, 1, 0];
let mut indices = [1, 4, 8].iter().copied();

let mut iter_zeros = bits.iter_zeros();
let mut compose = bits.iter()
  .copied()
  .enumerate()
  .filter_map(|(idx, bit)| if !bit { Some(idx) } else { None });

for ((a, b), c) in iter_zeros.zip(compose).zip(indices) {
  assert_eq!(a, b);
  assert_eq!(b, c);
}

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

Copies the bits from src into self.

The length of src must be the same as `self.

If src has the same type arguments as self, it can be more performant to use .copy_from_bitslice().

Original

slice::clone_from_bitslice

API Differences

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

Panics

This function will panic if the two slices have different lengths.

Examples

Cloning two bits from a slice into another:

use bitvec::prelude::*;

let src = bits![Msb0, u16; 1; 4];
let dst = bits![mut Lsb0, u8; 0; 2];

dst.clone_from_bitslice(&src[2 ..]);
assert_eq!(dst, bits![1; 2]);

Rust enforces that there can only be one mutable reference with no immutable references to a particular piece of data in a particular scope. Because of this, attempting to use clone_from_slice on a single slice will result in a compile failure:

use bitvec::prelude::*;

let slice = bits![mut 0, 0, 0, 1, 1];
slice[.. 2].clone_from_bitslice(&slice[3 ..]); // compile fail!

To work around this, we can use .split_at_mut() to create two distinct sub-slices from a slice:

use bitvec::prelude::*;

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

{
  let (left, right) = slice.split_at_mut(2);
  left.clone_from_bitslice(&right[1 ..]);
}

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

Performance

If self and src use the same type arguments, this specializes to .copy_from_bitslice(); if you know statically that this is the case, prefer to call that method directly and avoid the cost of detection at runtime. Otherwise, this is a bit-by-bit crawl across both slices, which is a slow process.

pub fn copy_from_bitslice(&mut self, src: &Self)

Copies all bits from src into self, using a memcpy wherever possible.

The length of src must be same as self.

If src does not use the same type arguments as self, use .clone_from_bitslice().

Original

slice::copy_from_slice

API Differences

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

Panics

This function will panic if the two slices have different lengths.

Examples

Copying two bits from a slice into another:

use bitvec::prelude::*;

let src = bits![1; 4];
let dst = bits![mut 0; 2];

// Because the slices have to be the same length,
// we slice the source slice from four bits to
// two. It will panic if we don't do this.
dst.clone_from_bitslice(&src[2..]);

Rust enforces that there can only be one mutable reference with no immutable references to a particular piece of data in a particular scope. Because of this, attempting to use [.copy_from_slice()] on a single slice will result in a compile failure:

use bitvec::prelude::*;

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

slice[.. 2].copy_from_bitslice(&bits[3 ..]); // compile fail!

To work around this, we can use .split_at_mut() to create two distinct sub-slices from a slice:

use bitvec::prelude::*;

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

{
  let (left, right) = slice.split_at_mut(2);
  left.copy_from_bitslice(&right[1 ..]);
}

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

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

Swaps all bits in self with those in other.

The length of other must be the same as self.

Original

slice::swap_with_slice

API Differences

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

Panics

This function will panic if the two 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 shift_left(&mut self, by: usize)

Shifts the contents of a bit-slice left (towards index 0).

This moves the contents of the slice from by .. down to 0 .. len - by, and erases len - by .. to 0. As this is a destructive (and linearly expensive) operation, you may prefer instead to use range subslicing.

Parameters

• &mut self
• by: The distance by which to shift the slice contents.

Panics

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

Examples

use bitvec::prelude::*;

let bits = bits![mut 1; 6];
bits.shift_left(2);
assert_eq!(bits, bits![1, 1, 1, 1, 0, 0]);

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

Shifts the contents of a bit-slice right (towards index self.len()).

This moves the contents of the slice from .. len - by up to by .., and erases .. by to 0. As this is a destructive (and linearly expensive) operation, you may prefer instead to use range subslicing.

Parameters

• &mut self
• by: The distance by which to shift the slice contents.

Panics

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

Examples

use bitvec::prelude::*;

let bits = bits![mut 1; 6];
bits.shift_right(2);
assert_eq!(bits, bits![0, 0, 1, 1, 1, 1]);

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

Sets all bits in the slice to a value.

Parameters

• &mut self
• value: The bit value to which all bits in the slice will be set.

Examples

use bitvec::prelude::*;

let mut src = 0u8;
let bits = src.view_bits_mut::<Msb0>();
bits[2 .. 6].set_all(true);
assert_eq!(bits.as_slice(), &[0b0011_1100]);
bits[3 .. 5].set_all(false);
assert_eq!(bits.as_slice(), &[0b0010_0100]);
bits[.. 1].set_all(true);
assert_eq!(bits.as_slice(), &[0b1010_0100]);

pub fn for_each<F>(&mut self, func: F) where
    F: FnMut(usize, bool) -> bool, 

Applies a function to each bit in the slice.

BitSlice cannot implement IndexMut, as it cannot manifest &mut bool references, and the BitRef proxy reference has an unavoidable overhead. This method bypasses both problems, by applying a function to each pair of index and value in the slice, without constructing a proxy reference. Benchmarks indicate that this method is about 2–4 times faster than the .iter_mut().enumerate() equivalent.

Parameters

• &mut self
• func: A function which receives two arguments, index: usize and value: bool, and returns a bool.

Effects

For each index in the slice, the result of invoking func with the index number and current bit value is written into the slice.

Examples

use bitvec::prelude::*;

let mut data = 0u8;
let bits = data.view_bits_mut::<Msb0>();
bits.for_each(|idx, _bit| idx % 3 == 0);
assert_eq!(data, 0b100_100_10);

pub fn offset_from(&self, other: &Self) -> isize

Produces the absolute offset in bits between two slice heads.

While this method is sound for any two arbitrary bit slices, the answer it produces is meaningful only when one argument is a strict subslice of the other. If the two slices are created from different buffers entirely, a comparison is undefined; if the two slices are disjoint regions of the same buffer, then the semantically correct distance is between the tail of the lower and the head of the upper, which this does not measure.

Visual Description

Consider the following sequence of bits:

[ 0 1 2 3 4 5 6 7 8 9 a b ]
  |       ^^^^^^^       |
  ^^^^^^^^^^^^^^^^^^^^^^^

It does not matter whether there are bits between the tail of the smaller and the larger slices. The offset is computed from the bit distance between the two heads.

Behavior

This function computes the semantic distance between the heads, rather than the *electrical. It does not take into account the BitOrder implementation of the slice.

Safety and Soundness

One of self or other must contain the other for this comparison to be meaningful.

Parameters

• &self
• other: Another bit slice. This must be either a strict subregion or a strict superregion of self.

Returns

The distance in (semantic) bits betwen the heads of each region. The value is positive when other is higher in the address space than self, and negative when other is lower in the address space than self.

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

Writes a new bit at a given index, without doing bounds checking.

This is generally not recommended; use with caution! Calling this method with an out-of-bounds index is undefined behavior. For a safe alternative, see .set().

Parameters

• &mut self
• index: The bit index at which to write. It must be in the range 0 .. self.len().
• value: The value to be written; true for 1 or false for 0.

Effects

The bit at index is set to value. If index is out of bounds, then the memory access is incorrect, and its behavior is unspecified.

Safety

This method is not safe. It performs raw pointer arithmetic to seek from the start of the slice to the requested index, and set the bit there. It does not inspect the length of self, and it is free to perform out-of-bounds memory write access.

Use this method only when you have already performed the bounds check, and can guarantee that the call occurs with a safely in-bounds index.

Examples

This example uses a bit slice of length 2, and demonstrates out-of-bounds access to the last bit in the element.

use bitvec::prelude::*;

let bits = bits![mut 0; 2];
let (first, _) = bits.split_at_mut(1);

unsafe {
  first.set_unchecked(1, true);
}

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

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

Writes a new bit at a given index, without doing bounds checking.

This method supports writing through a shared reference to a bit that may be observed by other BitSlice handles. It is only present when the T type parameter supports such shared mutation (measured by the Radium trait).

Effects

The bit at index is set to value. If index is out of bounds, then the memory access is incorrect, and its behavior is unspecified. If T is an atomic, this will lock the memory bus for the referent address, and may cause stalls.

Safety

This method is not safe. It performs raw pointer arithmetic to seek from the start of the slice to the requested index, and set the bit there. It does not inspect the length of self, and it is free to perform out-of-bounds memory write access.

Use this method only when you have already performed the bounds check, and can guarantee that the call occurs with a safely in-bounds index.

Examples

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

let byte = Cell::new(0u8);
let bits = byte.view_bits::<Msb0>();
let bits_2 = bits;

let (first, _) = bits.split_at(1);
assert_eq!(first.len(), 1);
unsafe { first.set_aliased_unchecked(2, true); }

assert!(bits_2[2]);

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

Swaps two bits in the slice.

See .swap().

Safety

a and b must both be less than self.len().

pub unsafe fn split_at_unchecked(&self, mid: usize) -> (&Self, &Self)

Divides one slice into two at an index, without performing any bounds checking.

See .split_at().

Safety

mid must not be greater than self.len(). If this condition is violated, the function behavior is unspecified.

Examples

use bitvec::prelude::*;

let bits = bits![0, 0, 0, 1, 1, 1];
let (l, r) = unsafe { bits.split_at_unchecked(3) };
assert!(l.not_any());
assert!(r.all());

let (l, r) = unsafe { bits.split_at_unchecked(6) };
assert_eq!(l, bits);
assert!(r.is_empty());

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

Divides one mutable slice into two at an index.

See .split_at_mut().

Safety

mid must not be greater than self.len().

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

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

The ranges 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.end() - src.start()].

Safety

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

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

Returns a raw bit-pointer to the base of the bit-slice’s region.

The caller must ensure that the bit-slice outlives the bit-pointer this function returns, or else it will end up pointing to garbage.

The caller must also ensure that the memory the bit-pointer (non-transitively) points to is never written to using this bit-pointer or any bit-pointer derived from it. If you need to mutate the contents of the slice, use .as_mut_bitptr().

Modifying the container referenced by this bit-slice may cause its buffer to be reällocated, which would also make any bit-pointers to it invalid.

Original

slice::as_ptr

API Differences

This returns a structure, BitPtr, rather than an actual raw pointer *Bit. The information required to address a bit within a memory element cannot be encoded into a single pointer.

This structure can be converted back into a &BitSlice with the function from_raw_parts.

Examples

use bitvec::prelude::*;

let x = bits![0, 0, 1];
let x_ptr = x.as_ptr();

unsafe {
  for i in 0 .. x.len() {
    assert_eq!(*x.get_unchecked(i), (&*x)[i]);
  }
}

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

Returns an unsafe mutable bit-pointer to the bit-slice’s region.

The caller must ensure that the bit-slice outlives the bit-pointer this function returns, or else it will end up pointing to garbage.

Modifying the container referenced by this bit-slice may cause its buffer to be reällocated, which would also make any bit-pointers to it invalid.

Original

slice::as_mut_ptr

API Differences

This returns *mut BitSlice, which is the equivalont of *mut [T] instead of *mut T. The pointer encoding used requires more than one CPU word of space to address a single bit, so there is no advantage to removing the length information from the encoded pointer value.

Examples

use bitvec::prelude::*;

let bits = bits![mut Lsb0, u8; 0; 8];
let bits_ptr = bits.as_mut_ptr();

for i in 0 .. bits.len() {
  unsafe {
    bits_ptr.add(i).write(i % 3 == 0);
  }
}
assert_eq!(bits.as_slice()[0], 0b0100_1001);

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

Returns the two raw bit-pointers spanning the bit-slice.

The returned range is half-open, which means that the end bit-pointer points one past the last bit of the bit-slice. This way, an empty bit-slice is represented by two equal bit-pointers, and the difference between the two bit-pointers represents the size of the bit-slice.

See as_bitptr for warnings on using these bit-pointers. The end bit-pointer requires extra caution, as it does not point to a valid bit in the bit-slice.

This function allows a more direct access to bit-pointers, without paying the cost of encoding into a *BitSlice, at the cost of no longer fitting into ordinary Rust interfaces.

Original

slice::as_ptr_range

API Differences

This returns a dedicated structure, rather than a range of BitPtrs, because the traits needed for non-core types to correctly operate in ranges are still unstable. The structure can be converted into a range, but that range will not be an iterator.

Examples

use bitvec::prelude::*;

let bits = bits![0, 1, 0, 0, 1];
let mid_ptr = bits.get(2).unwrap().into_bitptr();
let mut range = bits.as_bitptr_range();
assert!(range.contains(&mid_ptr));
unsafe {
  assert!(!range.next().unwrap().read());
  assert!(range.next_back().unwrap().read())
}

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

Returns the two unsafe mutable bit-pointers spanning the bit-slice.

The returned range is half-open, which means that the end bit-pointer points one past the last bitt of the bit-slice. This way, an empty bit-slice is represented by two equal bit-pointers, and the difference between the two bit-pointers represents the size of the bit-slice.

See as_mut_bitptr for warnings on using these bit-pointers. The end bit-pointer requires extra caution, as it does not point to a valid bit in the bit-slice.

Original

slice::as_mut_ptr_range

API Differences

This returns a dedicated structure, rather than a range of BitPtrs, because the traits needed for non-core types to correctly operate in ranges are still unstable. The structure can be converted into a range, but that range will not be an iterator.

Examples

use bitvec::prelude::*;
use bitvec::ptr as bv_ptr;

let mut data = 0u8;
let bits = data.view_bits_mut::<Msb0>();
for mut bitptr in bits.as_mut_bitptr_range() {
  unsafe { bv_ptr::write(bitptr, true); }
}
assert_eq!(data, !0);

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

Splits the slice into subslices at alias boundaries.

This splits self into the memory locations that it partially fills and the memory locations that it completely fills. The locations that are completely filled may be accessed without any bitvec-imposed alias conditions, while the locations that are only partially filled are left unchanged.

You can read more about the BitDomain splitting in its documentation.

Examples

use bitvec::prelude::*;

let mut data = [0u16; 3];
let all = data.view_bits_mut::<Msb0>();
let (_, rest) = all.split_at_mut(8);
let bits: &BitSlice<Msb0, <u16 as BitStore>::Alias> = &rest[.. 32];

let (head, body, tail) = bits
  .bit_domain()
  .region()
  .unwrap();
assert_eq!(head.len(), 8);
assert_eq!(tail.len(), 8);
let _: &BitSlice<Msb0, <u16 as BitStore>::Alias> = head;
let _: &BitSlice<Msb0, <u16 as BitStore>::Alias> = tail;
let _: &BitSlice<Msb0, u16> = body;

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

Splits the slice into subslices at alias boundaries.

This splits self into the memory locations that it partially fills and the memory locations that it completely fills. The locations that are completely filled may be accessed without any bitvec-imposed alias conditions, while the locations that are only partially filled are left unchanged.

You can read more about the BitDomainMut splitting in its documentation.

Examples

use bitvec::prelude::*;

let mut data = [0u16; 3];
let all = data.view_bits_mut::<Msb0>();
let (_, rest) = all.split_at_mut(8);
let bits: &mut BitSlice<Msb0, <u16 as BitStore>::Alias>
  = &mut rest[.. 32];

let (head, body, tail) = bits
  .bit_domain_mut()
  .region()
  .unwrap();
assert_eq!(head.len(), 8);
assert_eq!(tail.len(), 8);
let _: &mut BitSlice<Msb0, <u16 as BitStore>::Alias> = head;
let _: &mut BitSlice<Msb0, <u16 as BitStore>::Alias> = tail;
let _: &mut BitSlice<Msb0, u16> = body;

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

Views the underlying memory containing the slice, split at alias boundaries.

This splits self into the memory locations that it partially fills and the memory locatinos that it completely fills. The locations that are completely filled may be accessed without any bitvec-imposed alias conditions, while the locations that are only partially filled are left unchanged.

You can read more about the Domain splitting in its documentation.

Examples

use bitvec::prelude::*;

let mut data = [0u16; 3];
let all = data.view_bits_mut::<Msb0>();
let (_, rest) = all.split_at_mut(8);
let bits: &BitSlice<Msb0, <u16 as BitStore>::Alias> = &rest[.. 32];

let (head, body, tail) = bits
  .domain()
  .region()
  .unwrap();
assert_eq!(body.len(), 1);

let _: &<u16 as BitStore>::Alias = head.unwrap().1;
let _: &<u16 as BitStore>::Alias = tail.unwrap().0;
let _: &[u16] = body;

pub fn domain_mut(&mut self) -> DomainMut<'_, T>

Views the underlying memory containing the slice, split at alias boundaries.

This splits self into the memory locations that it partially fills and the memory locations that it completely fills. The locations that are completely filled may be accessed without any bitvec-imposed alias conditions, while the locations that are only partially filled are left unchanged.

You can read more about the DomainMut splitting in its documentation.

Examples

use bitvec::prelude::*;

let mut data = [0u16; 3];
let all = data.view_bits_mut::<Msb0>();
let (_, rest) = all.split_at_mut(8);
let bits: &mut BitSlice<Msb0, <u16 as BitStore>::Alias> = &mut rest[.. 32];

let (head, body, tail) = bits
  .domain_mut()
  .region()
  .unwrap();
assert_eq!(body.len(), 1);

let _: &<<u16 as BitStore>::Alias as BitStore>::Access = head.unwrap().1;
let _: &<<u16 as BitStore>::Alias as BitStore>::Access = tail.unwrap().0;
let _: &mut [u16] = body;

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

Views the underlying memory containing the slice.

The returned slice handle views all elements touched by self, and marks them all with self’s current aliasing state. For a more precise view, or one that permits mutation, use .domain() or .domain_mut().

pub fn split_at_aliased_mut(&mut self, mid: usize) -> (&mut Self, &mut Self)

Splits a mutable slice at some mid-point.

This method has the same behavior as .split_at_mut(), except that it does not apply an aliasing marker to the partitioned subslices.

Safety

Because this method is defined only on BitSlices whose T type is alias-safe, the subslices do not need to be additionally marked.

pub const MAX_BITS: usize

pub const MAX_ELTS: usize

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

Copies self into a new BitVec.

This resets any alias markings from self, since the returned buffer is known to be newly allocated and thus unaliased.

Examples

use bitvec::prelude::*;

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

Trait Implementations

impl<O, T> AsMut<BitSlice<O, T>> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Performs the conversion.

impl<O, T> AsRef<BitSlice<O, T>> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Performs the conversion.

impl<O, T> Binary for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Formats the value using the given formatter.

impl<O, T, Rhs> BitAnd<Rhs> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    BitSlice<O, T>: BitAndAssign<Rhs>, 

type Output = Self

The resulting type after applying the & operator.

fn bitand(self, rhs: Rhs) -> Self::Output

Performs the & operation.

impl<O, T, Rhs> BitAndAssign<Rhs> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    BitSlice<O, T>: BitAndAssign<Rhs>, 

fn bitand_assign(&mut self, rhs: Rhs)

Performs the &= operation.

impl<O, T> BitField for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    BitSlice<O, T>: BitField, 

fn load_le<M>(&self) -> M where
    M: BitMemory, 

Loads from self, using little-endian element T ordering.

fn load_be<M>(&self) -> M where
    M: BitMemory, 

Loads from self, using big-endian element T ordering.

fn store_le<M>(&mut self, value: M) where
    M: BitMemory, 

Stores into self, using little-endian element ordering.

fn store_be<M>(&mut self, value: M) where
    M: BitMemory, 

Stores into self, using big-endian element ordering.

fn load<M>(&self) -> M where
    M: BitMemory, 

Loads the bits in the self region into a local value.

fn store<M>(&mut self, value: M) where
    M: BitMemory, 

Stores a sequence of bits from the user into the domain of self.

impl<O, T, Rhs> BitOr<Rhs> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    BitSlice<O, T>: BitOrAssign<Rhs>, 

type Output = Self

The resulting type after applying the | operator.

fn bitor(self, rhs: Rhs) -> Self::Output

Performs the | operation.

impl<O, T, Rhs> BitOrAssign<Rhs> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    BitSlice<O, T>: BitOrAssign<Rhs>, 

fn bitor_assign(&mut self, rhs: Rhs)

Performs the |= operation.

impl<O, T, Rhs> BitXor<Rhs> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    BitSlice<O, T>: BitXorAssign<Rhs>, 

type Output = Self

The resulting type after applying the ^ operator.

fn bitxor(self, rhs: Rhs) -> Self::Output

Performs the ^ operation.

impl<O, T, Rhs> BitXorAssign<Rhs> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    BitSlice<O, T>: BitXorAssign<Rhs>, 

fn bitxor_assign(&mut self, rhs: Rhs)

Performs the ^= operation.

impl<O, T> Borrow<BitSlice<O, T>> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Immutably borrows from an owned value.

impl<O, T> BorrowMut<BitSlice<O, T>> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Mutably borrows from an owned value.

impl<O, T> Clone for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<O, T> Debug for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Formats the value using the given formatter.

impl<O, T> Default for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

fn default() -> Self

Returns the “default value” for a type.

impl<O, T> Deref for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

type Target = BitSlice<O, T>

The resulting type after dereferencing.

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

Dereferences the value.

impl<O, T> DerefMut for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Mutably dereferences the value.

impl<O, T> Display for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Formats the value using the given formatter.

impl<O, T> Drop for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

fn drop(&mut self)

Executes the destructor for this type.

impl<O, T> Eq for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

impl<'a, O, T> From<&'a BitSlice<O, T>> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

fn from(slice: &'a BitSlice<O, T>) -> Self

Performs the conversion.

impl<O, T> From<BitBox<O, T>> for BitVec<O, T> where
    O: BitOrder,
    T: BitStore, 

fn from(boxed: BitBox<O, T>) -> Self

Performs the conversion.

impl<O, T> From<BitVec<O, T>> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

fn from(bv: BitVec<O, T>) -> Self

Performs the conversion.

impl<O, T> Hash for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

fn hash<H>(&self, state: &mut H) where
    H: Hasher, 

Feeds this value into the given Hasher.

pub fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<O, T, Idx> Index<Idx> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    BitSlice<O, T>: Index<Idx>, 

type Output = <BitSlice<O, T> as Index<Idx>>::Output

The returned type after indexing.

fn index(&self, index: Idx) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<O, T, Idx> IndexMut<Idx> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    BitSlice<O, T>: IndexMut<Idx>, 

fn index_mut(&mut self, index: Idx) -> &mut Self::Output

Performs the mutable indexing (container[index]) operation.

impl<O, T> Into<Box<[T], Global>> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

fn into(self) -> Box<[T]>

Performs the conversion.

impl<O, T> IntoIterator for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

This is not present on Box<[T]>, but is needed to fit into the general operator implementations.

type IntoIter = <BitVec<O, T> as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

type Item = <Self::IntoIter as Iterator>::Item

The type of the elements being iterated over.

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<O, T> LowerHex for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Formats the value using the given formatter.

impl<O, T> Not for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

type Output = Self

The resulting type after applying the ! operator.

fn not(self) -> Self::Output

Performs the unary ! operation.

impl<O, T> Octal for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Formats the value using the given formatter.

impl<O, T> Ord for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<O1, O2, T1, T2> PartialEq<BitBox<O2, T2>> for BitSlice<O1, T1> where
    O1: BitOrder,
    O2: BitOrder,
    T1: BitStore,
    T2: BitStore, 

fn eq(&self, other: &BitBox<O2, T2>) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<O1, O2, T1, T2> PartialEq<BitBox<O2, T2>> for &BitSlice<O1, T1> where
    O1: BitOrder,
    O2: BitOrder,
    T1: BitStore,
    T2: BitStore, 

fn eq(&self, other: &BitBox<O2, T2>) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<O1, O2, T1, T2> PartialEq<BitBox<O2, T2>> for &mut BitSlice<O1, T1> where
    O1: BitOrder,
    O2: BitOrder,
    T1: BitStore,
    T2: BitStore, 

fn eq(&self, other: &BitBox<O2, T2>) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<O, T, Rhs: ?Sized> PartialEq<Rhs> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    Rhs: PartialEq<BitSlice<O, T>>, 

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<O1, O2, T1, T2> PartialOrd<BitBox<O2, T2>> for BitSlice<O1, T1> where
    O1: BitOrder,
    O2: BitOrder,
    T1: BitStore,
    T2: BitStore, 

fn partial_cmp(&self, other: &BitBox<O2, T2>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]pub fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]pub fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a, O1, O2, T1, T2> PartialOrd<BitBox<O2, T2>> for &'a BitSlice<O1, T1> where
    O1: BitOrder,
    O2: BitOrder,
    T1: BitStore,
    T2: BitStore, 

fn partial_cmp(&self, other: &BitBox<O2, T2>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]pub fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]pub fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a, O1, O2, T1, T2> PartialOrd<BitBox<O2, T2>> for &'a mut BitSlice<O1, T1> where
    O1: BitOrder,
    O2: BitOrder,
    T1: BitStore,
    T2: BitStore, 

fn partial_cmp(&self, other: &BitBox<O2, T2>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]pub fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]pub fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<O, T, Rhs: ?Sized> PartialOrd<Rhs> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore,
    Rhs: PartialOrd<BitSlice<O, T>>, 

fn partial_cmp(&self, other: &Rhs) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]pub fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]pub fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<O, T> Pointer for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Formats the value using the given formatter.

impl<O, T> Send for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

impl<O, T> Sync for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

impl<O, T> TryFrom<Box<[T], Global>> for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

type Error = Box<[T]>

The type returned in the event of a conversion error.

fn try_from(boxed: Box<[T]>) -> Result<Self, Self::Error>

Performs the conversion.

impl<O, T> Unpin for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

impl<O, T> UpperHex for BitBox<O, T> where
    O: BitOrder,
    T: BitStore, 

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

Formats the value using the given formatter.