Struct FixedBitSet 

pub struct FixedBitSet<const N: usize>(pub Vec<u8>);

A bit set with a fixed length of N bits.

A fixed bit set is encoded as exactly ceil(N / 8) bytes, without a length prefix. This differs from BitSet, which is prefixed by a VarInt and stores packed 64-bit words. The packed bytes follow the same bit order as Java’s BitSet.toByteArray: bit i is set when the following expression is non-zero:

(data[i / 8] & (1 << (i % 8))) != 0

The final byte is padded with zero bits when N is not divisible by eight.

Examples

use mcproto_types::{TypeCodec, basic::FixedBitSet};

// Bits 0, 7, and 8 are set in a nine-bit set.
let bits = FixedBitSet::<9>(vec![0b1000_0001, 0b0000_0001]);

let mut encoded = Vec::new();
bits.encode(&mut encoded)?;
assert_eq!(encoded, [0b1000_0001, 0b0000_0001]);

let mut input = encoded.as_slice();
assert_eq!(FixedBitSet::<9>::decode(&mut input)?, bits);
assert!(bits.contains(0));
assert!(bits.contains(7));
assert!(bits.contains(8));
assert!(!bits.contains(9));

Tuple Fields

0: Vec<u8>

The packed bytes, in little-endian bit order within each byte.

Implementations

impl<const N: usize> FixedBitSet<N>

pub const BYTE_LEN: usize

The number of packed bytes used by this fixed bit set.

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

Returns whether the bit at index is set.

Indices outside this set’s fixed length return false.

Trait Implementations

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

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

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

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

Formats the value using the given formatter.

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

fn default() -> FixedBitSet<N>

Returns the “default value” for a type.

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

impl<const N: usize> Hash for FixedBitSet<N>

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

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

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

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

Equality operator ==.

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

Inequality operator !=.

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

impl<const N: usize> TypeCodec for FixedBitSet<N>

fn encode(&self, writer: &mut impl Write) -> Result<(), CodecError>

Encodes this value to the writer.

fn decode(reader: &mut impl Read) -> Result<Self, CodecError>

Decodes this value from the reader.