Struct CdrWriter 

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

CDR writer for serialization.

Handles alignment and endianness for ROS 2 CDR encoding. Alignment is computed relative to origin — when a 4-byte CDR header is present, origin = 4 so that fields align correctly within the payload portion of the buffer.

Implementations

impl<'a> CdrWriter<'a>

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

Create a new CDR writer

pub fn new_at(buf: &'a mut [u8], pos: usize) -> Result<Self, SerError>

Create a CDR writer positioned at pos bytes into buf.

origin stays at 0, so alignment is computed relative to the start of buf. Used by FFI bridges that hand us a (origin, cursor, end) triple where buf = origin..end and the caller’s cursor is pos.

pub fn new_with_header(buf: &'a mut [u8]) -> Result<Self, SerError>

Create a new CDR writer with the 4-byte encapsulation header.

Writes [0x00, 0x01, 0x00, 0x00] (CDR little-endian) at the start and sets origin = 4 so subsequent alignment is relative to the payload, not the header. This is the normal entry point for serialising ROS 2 messages.

pub fn position(&self) -> usize

Get current position in buffer

pub fn remaining(&self) -> usize

Get remaining capacity

pub fn as_slice(&self) -> &[u8]

Get the written bytes

pub fn align(&mut self, alignment: usize) -> Result<(), SerError>

Align to the given boundary (relative to origin)

pub fn write_u8(&mut self, value: u8) -> Result<(), SerError>

Write a single byte without alignment

pub fn write_bool(&mut self, value: bool) -> Result<(), SerError>

Write a boolean (serialized as a single byte: 0 = false, 1 = true)

pub fn write_i8(&mut self, value: i8) -> Result<(), SerError>

Write i8 without alignment

pub fn write_bytes(&mut self, bytes: &[u8]) -> Result<(), SerError>

Write bytes without alignment

pub fn write_u16(&mut self, value: u16) -> Result<(), SerError>

Write u16 with alignment (little-endian)

pub fn write_u32(&mut self, value: u32) -> Result<(), SerError>

Write u32 with alignment (little-endian)

pub fn write_u64(&mut self, value: u64) -> Result<(), SerError>

Write u64 with alignment (little-endian)

pub fn write_i16(&mut self, value: i16) -> Result<(), SerError>

Write i16 with alignment (little-endian)

pub fn write_i32(&mut self, value: i32) -> Result<(), SerError>

Write i32 with alignment (little-endian)

pub fn write_i64(&mut self, value: i64) -> Result<(), SerError>

Write i64 with alignment (little-endian)

pub fn write_f32(&mut self, value: f32) -> Result<(), SerError>

Write f32 with alignment (little-endian)

pub fn write_f64(&mut self, value: f64) -> Result<(), SerError>

Write f64 with alignment (little-endian)

pub fn write_string(&mut self, s: &str) -> Result<(), SerError>

Write a CDR string (4-byte length including null + data + null terminator)

pub fn write_sequence_len(&mut self, len: usize) -> Result<(), SerError>

Write a sequence length (4-byte count)