enum-primitive-derive

This is a custom derive, using procedural macros, implementation of enum_primitive.

Documentation

https:/docs.rs/enum-primitive-derive/

Usage

Add the following to Cargo.toml:

[dependencies]
enum-primitive-derive = "^0.1"
num-traits = "^0.1"

Then to your code add:

#[macro_use]
extern crate enum_primitive_derive;
extern crate num_traits;

#[derive(Primitive)]
enum Variant {
    Value = 1,
    Another = 2,
}

To be really useful you need use num_traits::FromPrimitive or use num_traits::ToPrimitive or both. You will then be able to use num_traits::FromPrimitive and/or num_traits::ToPrimitive on your enum.

Full Example

#[macro_use]
extern crate enum_primitive_derive;
extern crate num_traits;

use num_traits::{FromPrimitive, ToPrimitive};

#[derive(Primitive)]
enum Foo {
    Bar = 32,
    Dead = 42,
    Beef = 50,
}

fn main() {
    assert_eq!(Foo::from_i32(32), Some(Foo::Bar));
    assert_eq!(Foo::from_i32(42), Some(Foo::Dead));
    assert_eq!(Foo::from_i64(50), Some(Foo::Beef));
    assert_eq!(Foo::from_isize(17), None);
    assert_eq!(Foo::Bar::to_i32(), Some(32));
    assert_eq!(Foo::Dead::to_isize(), Some(42));
}