Trait Tag

pub trait Tag: Sized {
    type Buf: AsMut<[u8]> + Send;

    const OFF: usize;
    const MIN: usize;

    // Required methods
    fn make_buf() -> Self::Buf;
    fn from_u8(x: u8) -> Option<Self>;
    fn as_bytes(&self) -> &'static [u8] ;
}

A type implementing Tag represents a static hash set of byte strings, with a very simple perfect hash function: every element has a unique discriminant at a common byte offset. The values of the type represent the members by this single discriminant byte; they are indices into the hash set.

Required Associated Constants

const OFF: usize

Discriminant offset

const MIN: usize

Minimum variant length

Required Associated Types

type Buf: AsMut<[u8]> + Send

Minimal suitably sized buffer for reading the wire representation

HACK: This is a workaround for const generics limitations.

Required Methods

fn make_buf() -> Self::Buf

Make an instance of Self::Buf

fn from_u8(x: u8) -> Option<Self>

Convert a discriminant into the corresponding variant

fn as_bytes(&self) -> &'static [u8]

Convert a variant back into the wire representation

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl Tag for Entry

const OFF: usize = 0usize

const MIN: usize = 16usize

type Buf = [u8; 32]

impl Tag for Node

const OFF: usize = 16usize

const MIN: usize = 24usize

type Buf = [u8; 40]