Enums

The Display derive works with enums. Each variant is rendered independently based on its kind (unit, tuple, named).

Default Style

use moxy::Display;

#[derive(Display)]
enum Shape {
    Circle(f64),
    Rect { width: f64, height: f64 },
    Point,
}

assert_eq!(Shape::Circle(3.14).to_string(), "Circle(3.14)");
assert_eq!(Shape::Rect { width: 4.0, height: 2.0 }.to_string(), "Rect { width: 4, height: 2 }");
assert_eq!(Shape::Point.to_string(), "Point");

Enum-Level Style

Apply a style to all variants at once:

use moxy::Display;

#[derive(Display)]
#[moxy(display(debug))]
enum Value {
    Text(String),
    Num(i32),
}

assert_eq!(Value::Text("hi".into()).to_string(), "Text(\"hi\")");
assert_eq!(Value::Num(42).to_string(), "Num(42)");

Per-Variant Overrides

Variant-level #[moxy(display(...))] overrides the enum-level style:

use moxy::Display;

#[derive(Display)]
#[moxy(display(debug))]
enum Token {
    #[moxy(display(compact))]
    Ident(String),
    Literal { value: String, kind: String },
}

// Ident uses compact (override), Literal uses debug (enum default)

Custom Format Strings

use moxy::Display;

#[derive(Display)]
enum Expr {
    #[moxy(display("{x}x{y}"))]
    Rect { x: i32, y: i32 },
    Point,
}

assert_eq!(Expr::Rect { x: 4, y: 2 }.to_string(), "4x2");
assert_eq!(Expr::Point.to_string(), "Point");

Field Attributes

skip and alias work within named variants:

use moxy::Display;

#[derive(Display)]
enum Entry {
    User {
        name: String,
        #[moxy(display(skip))]
        password: String,
    },
}

All struct-level styles work per-variant: debug, compact, keyvalue, map, json, color, pretty, alias.