#primitive #enum

macro cenum

A rust derive macro for C-style primitive enums

6 stable releases

1.1.1 Jan 12, 2022
1.0.3 Apr 9, 2020
1.0.2 Apr 8, 2020
1.0.1 Feb 27, 2020

#279 in Rust patterns

43 downloads per month
Used in 2 crates (via basin2-data)

GPL-3.0-or-later

16KB
143 lines

Cenum

Purpose

Cenum (C + Enum) is a small Rust crate that is a spiritual successor to the enum_primitive crate. It uses an attribute macro over a given enum to allow low-cost conversion from a field-less enum (discriminants are allowed) to a usize and back again.

Usage

use cenum::{ cenum, Cenum }; // exposed trait is Cenum

#[cenum]
enum MyEnum {
    Value0,
    Value1,
    Value7 = 7,
    Value8,
    Value9,
}

fn test() {
    let some_value = MyEnum::Value8;
    let serialized = some_value.to_primitive(); // to_u32/other primitive types also works
    let is_value_discriminant = MyEnum::is_discriminant(serialized);
    let deserialized = MyEnum::from_primitive(serialized); // panics if invalid value
    assert!(is_value_discriminant);
    assert_eq!(some_value, deserialized);
    assert_eq!(serialized, 8);
}

Dependencies

~280–700KB
~17K SLoC