- if chars.next() != Some('0') { return Some((i, ~"Expected '0'")); } i+=1;
- if chars.next() != Some('x') { return Some((i, ~"Expected 'x'")); } i+=1;
+ if chars.next() != Some('0') { return Some((i, "Expected '0'".to_owned())); } i+=1;
+ if chars.next() != Some('x') { return Some((i, "Expected 'x'".to_owned())); } i+=1;