Macro `TryFromPrimitive`

macro_rules! TryFromPrimitive { ... }

Implements TryFrom<Primitive> for a #[repr(Primitive)] enum.

Attempting to turn a primitive into an enum with `try_from`.

use num_enum::TryFromPrimitive;
use std::convert::TryFrom;

#[derive(Debug, Eq, PartialEq, TryFromPrimitive)]
#[repr(u8)]
enum Number {
    Zero,
    One,
}

let zero = Number::try_from(0u8);
assert_eq!(zero, Ok(Number::Zero));

let three = Number::try_from(3u8);
assert_eq!(
    three.unwrap_err().to_string(),
    "No discriminant in enum `Number` matches the value `3`",
);

Attempting to turn a primitive into an enum with try_from.

Attempting to turn a primitive into an enum with `try_from`.