1  fn main() {
 2      let s1 = gives_ownership();         // gives_ownership moves its return
 3                                          // value into s1
 4  
 5      let s2 = String::from("hello");     // s2 comes into scope
 6  
 7      let s3 = takes_and_gives_back(s2);  // s2 is moved into
 8                                          // takes_and_gives_back, which also
 9                                          // moves its return value into s3
10  
11      println!("{s1} {s3}");
12  } // Here, s3 goes out of scope and is dropped. s2 was moved, so nothing
13    // happens. s1 goes out of scope and is dropped.
14  
15  fn gives_ownership() -> String {             // gives_ownership will move its
16                                               // return value into the function
17                                               // that calls it
18  
19      let some_string = String::from("yours"); // some_string comes into scope
20  
21      some_string                              // some_string is returned and
22                                               // moves out to the calling
23                                               // function
24  }
25  
26  // This function takes a String and returns one
27  fn takes_and_gives_back(a_string: String) -> String { // a_string comes into
28                                                        // scope
29  
30      a_string  // a_string is returned and moves out to the calling function
31  }