Crate from_variants

Rust macro crate to automatically generate conversions from variant types into the target enum.

This crate requires Rust 1.45 or above to compile on stable.

Examples

use from_variants::FromVariants;

#[derive(Debug, Clone, PartialEq, Eq, FromVariants)]
pub enum Lorem {
    Str(String),
    Num(u16),
}

assert_eq!(Lorem::Num(10), Lorem::from(10));

You can skip variants to avoid type collisions:

use from_variants::FromVariants;

#[derive(Debug, Clone, PartialEq, Eq, FromVariants)]
pub enum Ipsum {
    Hello(String),

    #[from_variants(skip)]
    Goodbye(String),
}

assert_eq!(Ipsum::Hello("John".to_string()), Ipsum::from("John".to_string()));

Features

• Variant opt-out: To skip a variant, add #[from_variants(skip)] to that variant.
• Conversion opt-in: Use #[from_variants(into)] on an enum or variant to generate conversions that will automatically convert - for example, accepting a &str for a String variant. This must be used sparingly to avoid generating conflicting impls.
• no_std support: Generated conversions do not depend on the standard library.