README.md

Ownership

Refer to Ownership.

(gdb) list
5           // That way only one owner
6           let s2 = s1;
7           // cannot use s1 after the line above
8           // compiler error - value borrowed/used after
9           // move.
10          println!("s2 is {}", s2);
11      }
(gdb) print s1                                                                                       
$3 = "hello"
(gdb) print s2
$4 = "hello"
(gdb) print &s1
$5 = (*mut alloc::string::String) 0x7fffffffd928
(gdb) print &s2
$6 = (*mut alloc::string::String) 0x7fffffffd980

s1 and s2 are stored on the stack with the structure which holds the length, capacity, pointer to data on heap.

The image below shows the variable s2 goes out of scope after the block. And s1 was cleaned as it was borrowed in the block.

fn scoped_ownership_move() {
    let s1: String = String::from("scoped: hello");
    println!("s1: {}", s1);
    {
        let s2: String = s1;
        println!("s2: {}", s2);
    }
    println!("done");
}