single owner. borrowed references are "moved"

src/main.rs

@@ -1,12 +1,6 @@
 fn main() {
-    let a = 10;
-    println!("beginning a: {a}");
-    {
-        let a = "hello";
-        println!("inner a: {a}");
-
-        let a = true;
-        println!("shadowed a: {a}");
-    }
-    println!("ending a: {a}");
+    let s1 = String::from("hello");
+    let s2 = s1;
+    println!("{}", s2);
+    //println!("{}", s1);
 }