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);

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());

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());

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());

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]);

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]);

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]);

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]);

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());

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());

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());

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]);

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));
}

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);

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

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

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]);

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]);

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());

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]);

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());

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());

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]);
//                     ^^^^  ^^^^  ^

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]);

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 ^

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());

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 ^  ^^^^  ^^^^

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]);

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 ^

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]);

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]);

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());

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]);

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());

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]);

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());

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]);

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());

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]);

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());

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

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]));

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));

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));

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());

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());

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]);

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]);

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]);

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]);

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]);
//                                             ^  ^  ^  ^

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);

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);

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);

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.

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.

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.

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.

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

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

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);

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]);

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);

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]);

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]);

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.

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.

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.

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);

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.

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.

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.

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.

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);

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);

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);
}

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);
}

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));

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));

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));

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));

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);

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);

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);

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);

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());

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());

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());

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());

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());

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]);

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]);

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]);

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);

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);