Derive Macro VariantNames

#[derive(VariantNames)]
{
    // Attributes available to this derive:
    #[strum]
}

Implements Strum::VariantNames which adds an associated constant VARIANTS which is a 'static slice of discriminant names.

Adds an impl block for the enum that adds a static VARIANTS array of &'static str that are the discriminant names. This will respect the serialize_all attribute on the enum (like #[strum(serialize_all = "snake_case")].

// import the macros needed
use strum_macros::{EnumString};
// You need to import the trait, to have access to VARIANTS
use strum::VariantNames;

#[derive(Debug, EnumString, strum_macros::VariantNames)]
#[strum(serialize_all = "kebab-case")]
enum Color {
    Red,
    Blue,
    Yellow,
    RebeccaPurple,
}
assert_eq!(["red", "blue", "yellow", "rebecca-purple"], Color::VARIANTS);