impl<'a> FmtVisitor<'a> {
pub fn format_imports(&mut self, use_items: &[ptr::P<ast::Item>]) {
- let mut last_pos =
- use_items.first().map(|p_i| p_i.span.lo - BytePos(1)).unwrap_or(self.last_pos);
+ let mut last_pos = use_items.first()
+ .and_then(|p_i| p_i.span.lo.0.checked_sub(1))
+ .map(|span_lo| BytePos(span_lo))
+ .unwrap_or(self.last_pos);
let prefix = codemap::mk_sp(self.last_pos, last_pos);
let mut ordered_use_items = use_items.iter()
.map(|p_i| {