Convert NaiveDate::from_num_days_from_ce to return Result

src/naive/date/mod.rs

@@ -296,35 +296,34 @@ impl NaiveDate {
     ///
     /// # Errors
     ///
-    /// Returns `None` if the date is out of range.
+    /// Returns [`Error::OutOfRange`] if the date is out of range.
     ///
     /// # Example
     ///
     /// ```
-    /// use chrono::NaiveDate;
-    ///
+    /// # use chrono::{Error, NaiveDate};
     /// let from_ndays = NaiveDate::from_num_days_from_ce;
-    /// let from_ymd = |y, m, d| NaiveDate::from_ymd(y, m, d).unwrap();
+    /// let from_ymd = NaiveDate::from_ymd;
     ///
-    /// assert_eq!(from_ndays(730_000), Some(from_ymd(1999, 9, 3)));
-    /// assert_eq!(from_ndays(1), Some(from_ymd(1, 1, 1)));
-    /// assert_eq!(from_ndays(0), Some(from_ymd(0, 12, 31)));
-    /// assert_eq!(from_ndays(-1), Some(from_ymd(0, 12, 30)));
-    /// assert_eq!(from_ndays(100_000_000), None);
-    /// assert_eq!(from_ndays(-100_000_000), None);
-    /// ```
-    #[must_use]
-    pub const fn from_num_days_from_ce(days: i32) -> Option<NaiveDate> {
-        let days = try_opt!(days.checked_add(365)); // make December 31, 1 BCE equal to day 0
+    /// assert_eq!(from_ndays(730_000), from_ymd(1999, 9, 3));
+    /// assert_eq!(from_ndays(1), from_ymd(1, 1, 1));
+    /// assert_eq!(from_ndays(0), from_ymd(0, 12, 31));
+    /// assert_eq!(from_ndays(-1), from_ymd(0, 12, 30));
+    /// assert_eq!(from_ndays(100_000_000), Err(Error::OutOfRange));
+    /// assert_eq!(from_ndays(-100_000_000), Err(Error::OutOfRange));
+    /// # Ok::<(), Error>(())
+    /// ```
+    pub const fn from_num_days_from_ce(days: i32) -> Result<NaiveDate, Error> {
+        // make December 31, 1 BCE equal to day 0
+        let days = match days.checked_add(365) {
+            Some(d) => d,
+            None => return Err(Error::OutOfRange),
+        };
         let year_div_400 = days.div_euclid(146_097);
         let cycle = days.rem_euclid(146_097);
         let (year_mod_400, ordinal) = cycle_to_yo(cycle as u32);
         let flags = YearFlags::from_year_mod_400(year_mod_400 as i32);
-        ok!(NaiveDate::from_ordinal_and_flags(
-            year_div_400 * 400 + year_mod_400 as i32,
-            ordinal,
-            flags
-        ))
+        NaiveDate::from_ordinal_and_flags(year_div_400 * 400 + year_mod_400 as i32, ordinal, flags)
     }
 
     /// Makes a new `NaiveDate` by counting the number of occurrences of a particular day-of-week

src/naive/date/tests.rs

@@ -268,35 +268,35 @@ fn test_date_from_isoywd_and_iso_week() {
 #[test]
 fn test_date_from_num_days_from_ce() {
     let from_ndays_from_ce = NaiveDate::from_num_days_from_ce;
-    assert_eq!(from_ndays_from_ce(1), Some(NaiveDate::from_ymd(1, 1, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(2), Some(NaiveDate::from_ymd(1, 1, 2).unwrap()));
-    assert_eq!(from_ndays_from_ce(31), Some(NaiveDate::from_ymd(1, 1, 31).unwrap()));
-    assert_eq!(from_ndays_from_ce(32), Some(NaiveDate::from_ymd(1, 2, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(59), Some(NaiveDate::from_ymd(1, 2, 28).unwrap()));
-    assert_eq!(from_ndays_from_ce(60), Some(NaiveDate::from_ymd(1, 3, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(365), Some(NaiveDate::from_ymd(1, 12, 31).unwrap()));
-    assert_eq!(from_ndays_from_ce(365 + 1), Some(NaiveDate::from_ymd(2, 1, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(365 * 2 + 1), Some(NaiveDate::from_ymd(3, 1, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(365 * 3 + 1), Some(NaiveDate::from_ymd(4, 1, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(365 * 4 + 2), Some(NaiveDate::from_ymd(5, 1, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(146097 + 1), Some(NaiveDate::from_ymd(401, 1, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(146097 * 5 + 1), Some(NaiveDate::from_ymd(2001, 1, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(719163), Some(NaiveDate::from_ymd(1970, 1, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(0), Some(NaiveDate::from_ymd(0, 12, 31).unwrap())); // 1 BCE
-    assert_eq!(from_ndays_from_ce(-365), Some(NaiveDate::from_ymd(0, 1, 1).unwrap()));
-    assert_eq!(from_ndays_from_ce(-366), Some(NaiveDate::from_ymd(-1, 12, 31).unwrap())); // 2 BCE
+    assert_eq!(from_ndays_from_ce(1), NaiveDate::from_ymd(1, 1, 1));
+    assert_eq!(from_ndays_from_ce(2), NaiveDate::from_ymd(1, 1, 2));
+    assert_eq!(from_ndays_from_ce(31), NaiveDate::from_ymd(1, 1, 31));
+    assert_eq!(from_ndays_from_ce(32), NaiveDate::from_ymd(1, 2, 1));
+    assert_eq!(from_ndays_from_ce(59), NaiveDate::from_ymd(1, 2, 28));
+    assert_eq!(from_ndays_from_ce(60), NaiveDate::from_ymd(1, 3, 1));
+    assert_eq!(from_ndays_from_ce(365), NaiveDate::from_ymd(1, 12, 31));
+    assert_eq!(from_ndays_from_ce(365 + 1), NaiveDate::from_ymd(2, 1, 1));
+    assert_eq!(from_ndays_from_ce(365 * 2 + 1), NaiveDate::from_ymd(3, 1, 1));
+    assert_eq!(from_ndays_from_ce(365 * 3 + 1), NaiveDate::from_ymd(4, 1, 1));
+    assert_eq!(from_ndays_from_ce(365 * 4 + 2), NaiveDate::from_ymd(5, 1, 1));
+    assert_eq!(from_ndays_from_ce(146097 + 1), NaiveDate::from_ymd(401, 1, 1));
+    assert_eq!(from_ndays_from_ce(146097 * 5 + 1), NaiveDate::from_ymd(2001, 1, 1));
+    assert_eq!(from_ndays_from_ce(719163), NaiveDate::from_ymd(1970, 1, 1));
+    assert_eq!(from_ndays_from_ce(0), NaiveDate::from_ymd(0, 12, 31)); // 1 BCE
+    assert_eq!(from_ndays_from_ce(-365), NaiveDate::from_ymd(0, 1, 1));
+    assert_eq!(from_ndays_from_ce(-366), NaiveDate::from_ymd(-1, 12, 31)); // 2 BCE
 
     for days in (-9999..10001).map(|x| x * 100) {
-        assert_eq!(from_ndays_from_ce(days).map(|d| d.num_days_from_ce()), Some(days));
+        assert_eq!(from_ndays_from_ce(days).map(|d| d.num_days_from_ce()), Ok(days));
     }
 
-    assert_eq!(from_ndays_from_ce(NaiveDate::MIN.num_days_from_ce()), Some(NaiveDate::MIN));
-    assert_eq!(from_ndays_from_ce(NaiveDate::MIN.num_days_from_ce() - 1), None);
-    assert_eq!(from_ndays_from_ce(NaiveDate::MAX.num_days_from_ce()), Some(NaiveDate::MAX));
-    assert_eq!(from_ndays_from_ce(NaiveDate::MAX.num_days_from_ce() + 1), None);
+    assert_eq!(from_ndays_from_ce(NaiveDate::MIN.num_days_from_ce()), Ok(NaiveDate::MIN));
+    assert_eq!(from_ndays_from_ce(NaiveDate::MIN.num_days_from_ce() - 1), Err(Error::OutOfRange));
+    assert_eq!(from_ndays_from_ce(NaiveDate::MAX.num_days_from_ce()), Ok(NaiveDate::MAX));
+    assert_eq!(from_ndays_from_ce(NaiveDate::MAX.num_days_from_ce() + 1), Err(Error::OutOfRange));
 
-    assert_eq!(from_ndays_from_ce(i32::MIN), None);
-    assert_eq!(from_ndays_from_ce(i32::MAX), None);
+    assert_eq!(from_ndays_from_ce(i32::MIN), Err(Error::OutOfRange));
+    assert_eq!(from_ndays_from_ce(i32::MAX), Err(Error::OutOfRange));
 }
 
 #[test]

src/naive/datetime/mod.rs

@@ -238,7 +238,7 @@ impl NaiveDateTime {
         let date = NaiveDate::from_num_days_from_ce(try_opt!((days as i32).checked_add(719_163)));
         let time = NaiveTime::from_num_seconds_from_midnight(secs as u32, nsecs);
         match (date, time) {
-            (Some(date), Ok(time)) => Some(NaiveDateTime { date, time }),
+            (Ok(date), Ok(time)) => Some(NaiveDateTime { date, time }),
             (_, _) => None,
         }
     }