# light_enum


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A crate providing a derive keyword to generate a light enum.

## Usage

```shell
cargo add light_enum
```

This crate provide two derive keywords:
- `LightEnum` will generate a new enum without the content of each field
- `Values` will generate a vector containing each field of the enum

See examples bellow to understand what they do.

## LightEnum

```rust
use light_enum::LightEnum;

#[derive(LightEnum)]
enum MyEnum {
    A(i32, i32),
    B(i32),
    C,
}

let heavy = MyEnum::A(0, 0);
let light = heavy.to_light();
assert!(light == MyEnumLight::A);
```

`MyEnumLight` will be generated:

```rust
enum MyEnumLight {
    A,
    B,
    C,
}
```

## Values

```rust
use light_enum::Values;

#[derive(Values, PartialEq, Eq)]
enum Vals {
    A,
    B,
    C,
}

let values = Vals::VALUES;
assert!(values.len() == 3);
assert!(values.contains(&Vals::A));
assert!(values.contains(&Vals::B));
assert!(values.contains(&Vals::C));
```

Generated code:

```rust
impl Vals {
    const VALUES: [Vals; 3usize] = [Vals::A, Vals::B, Vals::C];
}
```

## Limitations

#### Values
Having a field with content will cause an error.

```rust
// this code will not compile
#[derive(Values)]
enum MyEnum {
    A(i32),
}
```

## Dev

The `cargo expand` utility is useful to see what is generated. It can be installed with `cargo install cargo-expand`.