#enum #primitive #macro #conversion #enum-primitive

enum_primitive

Macro to generate num::FromPrimitive instances for enum that works in Rust 1.0

4 releases

Uses old Rust 2015

0.1.1 Jan 9, 2017
0.1.0 Aug 13, 2015
0.0.2 Apr 8, 2015
0.0.1 Apr 7, 2015

#980 in Rust patterns

Download history 9439/week @ 2021-05-28 9416/week @ 2021-06-04 9220/week @ 2021-06-11 10150/week @ 2021-06-18 9786/week @ 2021-06-25 10739/week @ 2021-07-02 10398/week @ 2021-07-09 9058/week @ 2021-07-16 9297/week @ 2021-07-23 9138/week @ 2021-07-30 10974/week @ 2021-08-06 10153/week @ 2021-08-13 10737/week @ 2021-08-20 10001/week @ 2021-08-27 10242/week @ 2021-09-03 9334/week @ 2021-09-10

49,051 downloads per month
Used in less than 69 crates

MIT license

9KB
126 lines

enum_primitive Build Status

This crate exports a macro enum_from_primitive! that wraps an enum declaration and automatically adds an implementation of num::FromPrimitive (reexported here), to allow conversion from primitive integers to the enum. It therefore provides an alternative to the built-in #[derive(FromPrimitive)], which requires the unstable std::num::FromPrimitive and is disabled in Rust 1.0.

Documentation

https://andersk.github.io/enum_primitive-rs/enum_primitive/

Usage

Add the following to your Cargo.toml file:

[dependencies]
enum_primitive = "*"

Import the crate using #[macro_use] extern crate enum_primitive, and wrap your enum declaration inside the enum_from_primitive! macro.

Example

#[macro_use] extern crate enum_primitive;
extern crate num;
use num::FromPrimitive;

enum_from_primitive! {
#[derive(Debug, PartialEq)]
enum FooBar {
    Foo = 17,
    Bar = 42,
    Baz,
}
}

fn main() {
    assert_eq!(FooBar::from_i32(17), Some(FooBar::Foo));
    assert_eq!(FooBar::from_i32(42), Some(FooBar::Bar));
    assert_eq!(FooBar::from_i32(43), Some(FooBar::Baz));
    assert_eq!(FooBar::from_i32(91), None);
}

Dependencies

~205KB