# Deku
[](https://crates.io/crates/deku)
[](https://docs.rs/deku)
[](https://github.com/sharksforarms/deku/actions)
[](https://codecov.io/gh/sharksforarms/deku)
[](https://gitter.im/rust-deku/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
Declarative binary reading and writing
This crate provides bit-level, symmetric, serialization/deserialization
implementations for structs and enums
## Why use Deku
**Productivity**: Deku will generate symmetric reader/writer functions for your type!
Avoid the requirement of writing redundant, error-prone parsing and writing code
for binary structs or network headers
## Usage
```toml
[dependencies]
deku = "0.13"
```
no_std:
```toml
[dependencies]
deku = { version = "0.13", default-features = false, features = ["alloc"] }
```
## Example
See [documentation](https://docs.rs/deku) or
[examples](https://github.com/sharksforarms/deku/tree/master/examples) folder for more!
Read big-endian data into a struct, modify a value, and write it
```rust
use deku::prelude::*;
#[derive(Debug, PartialEq, DekuRead, DekuWrite)]
#[deku(endian = "big")]
struct DekuTest {
#[deku(bits = "4")]
field_a: u8,
#[deku(bits = "4")]
field_b: u8,
field_c: u16,
}
fn main() {
let data: Vec<u8> = vec![0b0110_1001, 0xBE, 0xEF];
let (_rest, mut val) = DekuTest::from_bytes((data.as_ref(), 0)).unwrap();
assert_eq!(DekuTest {
field_a: 0b0110,
field_b: 0b1001,
field_c: 0xBEEF,
}, val);
val.field_c = 0xC0FE;
let data_out = val.to_bytes().unwrap();
assert_eq!(vec![0b0110_1001, 0xC0, 0xFE], data_out);
}
```
## Changelog
See [CHANGELOG.md](https://github.com/sharksforarms/deku/blob/master/CHANGELOG.md)