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

   1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 pub fn main() {
  12     // Make sure we properly handle repeated self-appends.
  13     let mut a: String = "A".to_string();
  14     let mut i = 20;
  15     let mut expected_len = 1;
  16     while i > 0 {
  17         println!("{}", a.len());
  18         assert_eq!(a.len(), expected_len);
  19         a = format!("{}{}", a, a);
  20         i -= 1;
  21         expected_len *= 2;
  22     }
  23 }