Explicit return borrowing fun

rustbook/ownership/src/main.rs

@@ -1,11 +1,13 @@
 fn main() {
-    let x = 5;
-    let y = x;
-
-    println!("x = {}, y = {}", x, y);
-
     let s1 = String::from("hello");
-    let s2 = s1.clone();
 
-    println!("s1 = {}, s2 = {}", s1, s2);
+    let (s2, len) = calculate_length(s1);
+
+    println!("The length of '{}' is {}.", s2, len);
+}
+
+fn calculate_length(s: String) -> (String, usize) {
+    let length = s.len();
+
+    (s, length)
 }