work

src/ir/id.rs

@@ -0,0 +1,54 @@
+use std::ops::{Index, IndexMut};
+
+pub struct Id<T> {
+    idx: usize,
+    _pd: std::marker::PhantomData<T>,
+}
+
+pub struct IdVec<T> {
+    vec: Vec<T>,
+}
+
+impl<T> IdVec<T> {
+    pub fn add(&mut self, val: T) -> Id<T> {
+        let id = Id {
+            idx: self.vec.len(),
+            _pd: Default::default(),
+        };
+        self.vec.push(val);
+        id
+    }
+}
+
+impl<T> Index<Id<T>> for IdVec<T> {
+    type Output = T;
+
+    fn index(&self, index: Id<T>) -> &Self::Output {
+        &self.vec[index.idx]
+    }
+}
+
+impl<T> IndexMut<Id<T>> for IdVec<T> {
+    fn index_mut(&mut self, index: Id<T>) -> &mut Self::Output {
+        &mut self.vec[index.idx]
+    }
+}
+
+impl<T> Default for IdVec<T> {
+    fn default() -> Self {
+        Self {
+            vec: Default::default(),
+        }
+    }
+}
+
+impl<T> Clone for Id<T> {
+    fn clone(&self) -> Self {
+        Self {
+            idx: self.idx.clone(),
+            _pd: self._pd.clone(),
+        }
+    }
+}
+
+impl<T> Copy for Id<T> {}