added notes in unsafe-rust-is-cpp

unsafe-rust-is-cpp/src/main.rs

@@ -36,6 +36,10 @@ pub fn rust_like_its_2025() {
     // So far this is the same. Let's move the rest to a function.
     println!("OUTPUT: {}", foo(n_mut1, n_mut2));
 
+    // This works if you compile on debug.
+    // It also works if `foo` is hinted as never inlined.
+    // But it won't work anymore if non-inlined and compiled in release!
+    
     // You can't code in unsafe Rust like it's C++.
     // Unsafe Rust does not allow you to jump over the borrow rules.
     // It merely stops preventing you from trying.