Derive Macro IsVariant 

#[derive(IsVariant)]
{
    // Attributes available to this derive:
    #[is_variant]
}

#[derive(IsVariant)] — auto-implement pub const fn is_<variant>(&self) -> bool for every variant.

Attributes

• Per-variant #[is_variant(name = "explicit")] overrides the auto-derived method-name suffix (default is the snake-cased variant identifier).

Compounding: pairs with #[derive(Discriminant)] for variant→name reflection and #[derive(TypedDispatcher)] for variant→consumer dispatch.