BitWrap

BitWrap is a derive macro and trait to declare a struct data member with explicit size, in bits.

BitWrapExt Trait

Trait declares 2 methods:

rust fn pack(&self, dst: &mut [u8]) -> Result<usize, BitWrapError>

pack method serialize struct fields into dst array

rust fn unpack(&mut self, src: &[u8]) -> Result<usize, BitWrapError>

unpack method deserialize struct fields from src array

BitWrap Macro

```rust use bitwrap::{BitWrap, BitWrapExt};

[derive(BitWrap)]

struct Packet { // single bit field #[bitfield(1)] field_1: u8,

// single bit field as boolean:
// - 0 - false
// - 1 - true
#[bitfield]
field_2: bool,

// virtual field with option `name`
// unpack reads bits to the internall variable `_reserved`
// pack sets 6 bits from defined `value`
#[bitfield(6, name = _reserved, value = 0b111111)]

// call BitWrapExt methods for Ipv4Addr
#[bitfield]
ip: std::net::Ipv4Addr

// byte array
#[bitfield]
mac: [u8; 6],

// virtual field with optn `name` to define buffer length
#[bitfield(8, name = data_len, value = self.data.len())]

// get slice of `data_len` bytes and call BitWrapExt method for Vec<T>
// where T is u8 or with implemented BitWrapExt + Default traits
#[bitfield(data_len)]
data: Vec<u8>,

} ```