src/bin/generic_trait_type_erasure.rs

@@ -0,0 +1,37 @@
+
+
+pub trait Repository {
+    type Key;
+
+    fn get_data(&self, key: Self::Key) -> String;
+    fn set_data(&self, key: Self::Key, value: String);
+}
+
+use std::any::Any;
+
+trait Key: Any {
+    fn as_any(&self) -> &dyn Any;
+    fn from_str(s: &str) -> Self where Self: Sized;
+    fn to_string(&self) -> String;
+}
+
+impl<T: Any> Key for T {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+}
+
+impl Key for String {
+    fn from_str(s: &str) -> Self {
+        s.to_string()
+    }
+
+    fn to_string(&self) -> String {
+        self.clone()
+    }
+}
+
+pub trait RepositoryTypeErased {
+    fn get_data(&self, key: Key) -> String;
+    fn set_data(&self, key: Key, value: String);
+}