strftime: yield None early

Author: djc

src/format/strftime.rs

@@ -431,12 +431,9 @@ impl<'a> StrftimeItems<'a> {
  use Item::{Literal, Space};
  use Numeric::*;
 
- match remainder.chars().next() {
- // we are done
- None => None,
-
+ match remainder.chars().next()? {
  // the next item is a specifier
- Some('%') => {
+ '%' => {
  let original = remainder;
  remainder = &remainder[1..];
  let mut error_len = 0;
@@ -664,7 +661,7 @@ impl<'a> StrftimeItems<'a> {
  }
 
  // the next item is space
- Some(c) if c.is_whitespace() => {
+ c if c.is_whitespace() => {
  // `%` is not a whitespace, so `c != '%'` is redundant
  let nextspec =
  remainder.find(|c: char| !c.is_whitespace()).unwrap_or(remainder.len());