asterinas/ostd/libs/int-to-c-enum

TryFromInt - A convenient derive macro for converting an integer to an enum

Quick Start

To use this crate, first add this crate to your Cargo.toml.

[dependencies]
int-to-c-enum = "0.1.0"

You can use this macro for a C-like enum.

use int_to_c_enum::TryFromInt;
#[repr(u8)]
#[derive(TryFromInt, Debug)]
pub enum Color {
    Red = 1,
    Blue = 2,
    Green = 3,
}

Then, you can use try_from function for this enum.

fn main() {
    let color = Color::try_from(1).unwrap();
    println!("color = {color:?}"); // color = Red;
}

Introduction

This crate provides a derive procedural macro named TryFromInt. This macro will automatically implement TryFrom trait for enums that meet the following requirements:

1. The enum must have a primitive repr, i.e., the enum should have attribute like #[repr(u8)], #[repr(u32)], etc. The type parameter of TryFrom will be the repr, e.g., in the QuickStart example, the macro will implement TryFrom<u8> for Color.
2. The enum must consist solely of unit variants, which is called units only enum. Each field should have an explicit discriminant.