Struct BitWriter 

pub struct BitWriter<'a> { /* private fields */ }

Writes packed bits to a caller-supplied byte slice, most-significant-bit first.

The cursor zero-fills bytes lazily as it advances, so callers can pass an uninitialized-looking buffer and read out only the prefix returned by BitWriter::finish.

Example

use wire_codec::BitWriter;

let mut storage = [0u8; 1];
let mut w = BitWriter::new(&mut storage);
w.write_bits(0b101, 3).unwrap();
w.write_bits(0b01100, 5).unwrap();
assert_eq!(w.finish(), 1);
assert_eq!(storage[0], 0xAC);

Implementations

impl<'a> BitWriter<'a>

pub fn new(bytes: &'a mut [u8]) -> Self

Wrap bytes in a new bit cursor. Existing contents of bytes are overwritten as bits are written.

pub fn bits_written(&self) -> usize

Number of bits written so far.

pub fn align_to_byte(&mut self) -> Result<()>

Pad the cursor with zero bits up to the next byte boundary.

Errors

Returns Error::BufferFull if rounding up would exceed the backing slice.

pub fn write_bits(&mut self, value: u64, n: u32) -> Result<()>

Write the low n bits of value into the buffer.

Errors

• Error::BitOverflow if n is 0, greater than MAX_BIT_WIDTH, or value has bits set above position n.
• Error::BufferFull if fewer than n bits remain in the buffer.

pub fn finish(self) -> usize

Finalize writes and return the number of whole bytes consumed.

A partially-filled trailing byte counts as one full byte, with the remaining low-order bits left zero-padded.

Trait Implementations

impl<'a> Debug for BitWriter<'a>

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

Formats the value using the given formatter.