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#[derive(Copy, Clone, PartialEq, Hash, Eq, Debug, Ord, PartialOrd, Default)]
pub struct Entity(pub u32);
impl From<u32> for Entity {
fn from(u: u32) -> Self {
Entity(u)
}
}
pub trait EntityStore {
fn register_entity(&mut self, entity: impl Into<Entity>);
fn remove_entity(&mut self, entity: impl Into<Entity>);
}
#[derive(Default)]
pub struct VecEntityStore {
pub inner: Vec<Entity>,
}
impl EntityStore for VecEntityStore {
fn register_entity(&mut self, entity: impl Into<Entity>) {
self.inner.push(entity.into());
}
fn remove_entity(&mut self, entity: impl Into<Entity>) {
let entity = entity.into();
self.inner
.iter()
.position(|&n| n == entity)
.map(|e| self.inner.remove(e));
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_entity_from() {
let entity = Entity::from(2);
assert_eq!(entity.0, 2);
let entity = Entity::from(5);
assert_eq!(entity.0, 5);
}
#[test]
fn test_register_entity() {
let mut store = VecEntityStore::default();
let entity_one = Entity::from(1);
store.register_entity(entity_one);
let entity_two = Entity::from(2);
store.register_entity(entity_two);
let entity_three = Entity::from(3);
assert!(store.inner.contains(&entity_one));
assert!(store.inner.contains(&entity_two));
assert!(!store.inner.contains(&entity_three));
}
#[test]
fn test_remove_entity() {
let mut store = VecEntityStore::default();
let entity_one = Entity::from(1);
store.inner.push(entity_one);
let entity_two = Entity::from(2);
store.inner.push(entity_two);
store.remove_entity(entity_one);
assert!(!store.inner.contains(&entity_one));
assert!(store.inner.contains(&entity_two));
}
}