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# enum_primitive [](https://travis-ci.org/andersk/enum_primitive-rs)
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
```rust
#[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);
}
```
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