/src/test/run-pass/string-self-append.rs

 1use std;
 2import str;
 3
 4fn main() {
 5    // Make sure we properly handle repeated self-appends.
 6    let mut a: ~str = ~"A";
 7    let mut i = 20;
 8    let mut expected_len = 1u;
 9    while i > 0 {
10        log(error, str::len(a));
11        assert (str::len(a) == expected_len);
12        a += a;
13        i -= 1;
14        expected_len *= 2u;
15    }
16}