diff --git a/bindings/rust/cxx-sample/src/main.rs b/bindings/rust/cxx-sample/src/main.rs
index 0a6e28f..adbae0f 100644
--- a/bindings/rust/cxx-sample/src/main.rs
+++ b/bindings/rust/cxx-sample/src/main.rs
@@ -14,6 +14,7 @@ mod ffi {
     }
 }
 
+// missing step: separate lib from app 
 fn main() {
     let a = 10;
     let b = 5;