Implement native RLV state and permissions (#79)

crates/libremetaverse-types/src/compat.rs

@@ -1151,7 +1151,100 @@ impl<T> Future for AsyncEnumerableNext<T> {
     }
 }
 
-pub struct ImmutableDictionary<TKey, TValue>(pub PhantomData<fn(TKey, TValue)>);
+/// Read-only, cheaply clonable hash-map snapshot corresponding to
+/// `System.Collections.Immutable.ImmutableDictionary<TKey, TValue>`.
+#[derive(Clone, Debug)]
+pub struct ImmutableDictionary<TKey, TValue>(Arc<std::collections::HashMap<TKey, TValue>>);
+
+impl<TKey, TValue> PartialEq for ImmutableDictionary<TKey, TValue>
+where
+    TKey: Eq + std::hash::Hash,
+    TValue: PartialEq,
+{
+    fn eq(&self, other: &Self) -> bool {
+        self.0 == other.0
+    }
+}
+
+impl<TKey, TValue> Eq for ImmutableDictionary<TKey, TValue>
+where
+    TKey: Eq + std::hash::Hash,
+    TValue: Eq,
+{
+}
+
+impl<TKey, TValue> ImmutableDictionary<TKey, TValue> {
+    /// Creates an immutable snapshot from an owned map.
+    #[must_use]
+    pub fn from_map(values: std::collections::HashMap<TKey, TValue>) -> Self {
+        Self(Arc::new(values))
+    }
+
+    /// Returns the number of entries in the snapshot.
+    #[must_use]
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    /// Returns whether the snapshot contains no entries.
+    #[must_use]
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    /// Iterates over keys and values in the snapshot.
+    #[must_use]
+    pub fn iter(&self) -> std::collections::hash_map::Iter<'_, TKey, TValue> {
+        self.0.iter()
+    }
+
+    /// Iterates over values in the snapshot.
+    #[must_use]
+    pub fn values(&self) -> std::collections::hash_map::Values<'_, TKey, TValue> {
+        self.0.values()
+    }
+
+    /// Looks up a value by borrowed key.
+    #[must_use]
+    pub fn get<Q>(&self, key: &Q) -> Option<&TValue>
+    where
+        TKey: std::borrow::Borrow<Q> + Eq + std::hash::Hash,
+        Q: Eq + std::hash::Hash + ?Sized,
+    {
+        self.0.get(key)
+    }
+}
+
+impl<TKey, TValue> Default for ImmutableDictionary<TKey, TValue> {
+    fn default() -> Self {
+        Self(Arc::new(std::collections::HashMap::new()))
+    }
+}
+
+impl<TKey, TValue> From<std::collections::HashMap<TKey, TValue>>
+    for ImmutableDictionary<TKey, TValue>
+{
+    fn from(values: std::collections::HashMap<TKey, TValue>) -> Self {
+        Self::from_map(values)
+    }
+}
+
+impl<TKey, TValue> std::ops::Deref for ImmutableDictionary<TKey, TValue> {
+    type Target = std::collections::HashMap<TKey, TValue>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<'a, TKey, TValue> IntoIterator for &'a ImmutableDictionary<TKey, TValue> {
+    type Item = (&'a TKey, &'a TValue);
+    type IntoIter = std::collections::hash_map::Iter<'a, TKey, TValue>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
 
 /// Read-only, cheaply clonable snapshot corresponding to
 /// `System.Collections.Immutable.ImmutableList<T>`.