2 unstable releases
Uses old Rust 2015
0.2.0 | Mar 20, 2019 |
---|---|
0.1.0 | Aug 8, 2018 |
#2191 in Rust patterns
217 downloads per month
Used in 5 crates
(via kompact)
14KB
319 lines
bitfields-rs
Helpers for storing sub-byte enums in primitive types.
Example
fn example() {
// Could either be handwritten or extracted from a serialized network buffer
let mut storage = vec![0u8];
// write TCP bits
storage.store(Transport::TCP).unwrap();
// write address type bits
storage.store(AddressType::IPv4).unwrap();
// retrieve as named enums from positions indicated by `BitField` implementations
assert_eq!(storage.get_as::<Transport>().unwrap(), Transport::TCP);
assert_eq!(storage.get_as::<AddressType>().unwrap(), AddressType::IPv4);
}
#[derive(Debug, PartialEq)]
#[repr(u8)]
enum Transport {
TCP = 0b01,
UDP = 0b10,
UDT = 0b11,
}
#[derive(Debug, PartialEq)]
#[repr(u8)]
pub enum AddressType {
IPv4 = 0,
IPv6 = 1,
DomainName = 2,
}
impl BitField for Transport {
const POS: usize = 0;
const WIDTH: usize = 2;
}
impl BitField for AddressType {
const POS: usize = 2;
const WIDTH: usize = 2;
}
impl Into<u8> for AddressType {
fn into(self) -> u8 {
self as u8
}
}
impl Into<u8> for Transport {
fn into(self) -> u8 {
self as u8
}
}
impl TryFrom<u8> for AddressType {
type Error = SerError;
fn try_from(x: u8) -> Result<Self, Self::Error> {
match x {
x if x == AddressType::IPv4 as u8 => Ok(AddressType::IPv4),
x if x == AddressType::IPv6 as u8 => Ok(AddressType::IPv6),
_ => Err(SerError::InvalidType("Unsupported AddressType".into())),
}
}
}
impl TryFrom<u8> for Transport {
type Error = ();
fn try_from(value: u8) -> Result<Self, Self::Error> {
match value {
0b01 => Ok(Transport::TCP),
0b10 => Ok(Transport::UDP),
0b11 => Ok(Transport::UDT),
_ => Err(()),
}
}
}