Integral enum

Rust derive-macro that simplifies integral enum creation

Example

use integral_enum::IntegralEnum;

/// Simple meaningful enum
/// (!) repr attribute defaults to u8, to specify custom repr 
/// use built-in attribute #[repr(integral_value)] it
/// can contain only integral values
/// like u8, u16, u32, u64, u128 and its signed equivalents.
/// 
/// WARNING: if no explicit #[repr(...)] specified u8 will be used
/// as the underlying integral type, actual enum still can have u16 representation,
/// for example. For most cases this is enough, but if your enum is large
/// enough - specify explicit representation.
/// FIXME: Add automatic representation determining
#[derive(IntegralEnum)]
pub enum Emotion {
    Pain,
    Hatred,
}

// Test it
assert_eq!(Emotion::try_from(0), Ok(Emotion::Pain));
assert_eq!(Emotion::try_from(1), Ok(Emotion::Hatred));
assert_eq!(Emotion::try_from(123), Err(()));

Macro will automatically generate the following trait implementations: TryFrom, Clone, Copy, PartialEq, Eq, Display, Debug

if you want to disable certain implementation, consider the #[enum_disable(...)] attribute, items can be: clone, copy, display, debug, total_eq, partial_eq, try_from

• Some of these attributes are dependant, for example Copy depends on Clone, so if you disable Clone generation, Copy generation will be disabled also.
• total_eq disables Eq trait implementation

Example:

use integral_enum::IntegralEnum;

#[derive(IntegralEnum)]
#[enum_disable(display)]
pub enum Emotion {
    Pain,
    Hatred,
}

println!("{}", Emotion::Pain); // Compile error

TODO

• Do we really need to implement PartialOrd + Ord also?