Trait EntityId 

pub trait EntityId:
    ValueObject
    + Eq
    + Hash
    + Ord
    + Display { }

A ValueObject used as an crate::domain::Entity’s identity: always structurally comparable, hashable, orderable, and displayable, so it can be used as a map key, sorted, and printed.

Examples

use ddd_toolkit_core::domain::{EntityId, ValueObject};
use std::collections::HashMap;
use std::fmt::Display;

#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
struct OrderId(u32);

impl ValueObject for OrderId {}

impl Display for OrderId {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "order-{}", self.0)
    }
}

impl EntityId for OrderId {}

// usable as a map key...
let orders: HashMap<OrderId, &str> = HashMap::from([(OrderId(1), "pending")]);
assert_eq!(orders.get(&OrderId(1)), Some(&"pending"));

// ...sortable...
let mut ids = vec![OrderId(3), OrderId(1), OrderId(2)];
ids.sort();
assert_eq!(ids, vec![OrderId(1), OrderId(2), OrderId(3)]);

// ...and printable.
assert_eq!(OrderId(1).to_string(), "order-1");

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors