document Zone::from_ref()

src/world/zone.rs

@@ -19,6 +19,29 @@ pub struct Zone {
 }
 
 impl Zone {
+	/// Create a new `Zone` from a `&Zone`.
+	///
+	/// # Arguments
+	///
+	/// * `zone: &Zone` : Reference to a `Zone`
+	///
+	/// # Examples
+	///
+	/// ```
+	/// use std::collections::HashSet;
+	/// use rude::id::Id;
+	/// use rude::world::Zone;
+	///
+	/// let zone = Zone {
+	///     id: Id::new(),
+	///     parent: Id::new(),
+	///     name: "Zone".into(),
+	///     users_visible: false,
+	///     areas: HashSet::new(),
+	/// };
+	///
+	/// assert_eq!(zone, Zone::from_ref(&zone));
+	/// ```
 	pub fn from_ref(zone: &Self) -> Self {
 		Self {
 			id: zone.id,