Trait Enum

pub trait Enum: Sized {
    const LENGTH: usize;

    // Required methods
    fn from_usize(value: usize) -> Self;
    fn into_usize(self) -> usize;
}

Enum mapping type.

This trait is implemented by #[derive(Enum)].

This trait is also implemented by bool and u8. While u8 is strictly speaking not an actual enum, there are good reasons to consider it like one, as array of u8 keys is a relatively common pattern.

Required Associated Constants

const LENGTH: usize

Length of the enum.

Required Methods

fn from_usize(value: usize) -> Self

Takes an usize, and returns an element matching into_usize function.

fn into_usize(self) -> usize

Returns an unique identifier for a value within range of 0..Array::LENGTH.

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.

Implementations on Foreign Types

impl Enum for Ordering

const LENGTH: usize = 3usize

fn from_usize(value: usize) -> Self

fn into_usize(self) -> usize

impl Enum for Infallible

const LENGTH: usize = 0usize

fn from_usize(_: usize) -> Self

fn into_usize(self) -> usize

impl Enum for bool

const LENGTH: usize = 2usize

fn from_usize(value: usize) -> Self

fn into_usize(self) -> usize

impl Enum for u8

const LENGTH: usize = 256usize

fn from_usize(value: usize) -> Self

fn into_usize(self) -> usize

impl Enum for ()

const LENGTH: usize = 1usize

fn from_usize(value: usize) -> Self

fn into_usize(self) -> usize

Implementors