static ids

src/util/id.rs

@@ -37,4 +37,20 @@ impl Id {
     pub fn duplicate(&self) -> Self {
         Self(self.0)
     }
+
+    /// this must be used carefully to make sure
+    /// all IDs are still valid references.
+    /// generally should not be used in "user" code
+    pub fn copyable(&self) -> CopyId {
+        CopyId(self.0)
+    }
+}
+
+#[derive(Eq, Hash, PartialEq, Debug, Clone, Copy)]
+pub struct CopyId(u64);
+
+impl CopyId {
+    pub fn id(&self) -> Id {
+        Id(self.0)
+    }
 }