replace Datelike::days_between with NaiveDate::abs_diff

Author: Kinrany

src/naive/date/mod.rs

@@ -1148,7 +1148,7 @@ impl NaiveDate {
     /// );
     /// ```
     #[must_use]
-    pub const fn signed_duration_since(self, rhs: NaiveDate) -> TimeDelta {
+    pub const fn signed_duration_since(self, rhs: Self) -> TimeDelta {
         let year1 = self.year();
         let year2 = rhs.year();
         let (year1_div_400, year1_mod_400) = div_mod_floor(year1, 400);
@@ -1161,6 +1161,24 @@ impl NaiveDate {
         expect(TimeDelta::try_days(days), "always in range")
     }
 
+    /// Returns the absolute difference between two `NaiveDate`s measured as the number of days.
+    ///
+    /// This is always an integer, non-negative number, similar to `abs_diff` in `std`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use chrono::{Days, NaiveDate};
+    /// #
+    /// let date1: NaiveDate = "2020-01-01".parse().unwrap();
+    /// let date2: NaiveDate = "2020-01-31".parse().unwrap();
+    /// assert_eq!(date2.abs_diff(date1), Days::new(30));
+    /// assert_eq!(date1.abs_diff(date2), Days::new(30));
+    /// ```
+    pub const fn abs_diff(self, rhs: Self) -> Days {
+        Days::new(i32::abs_diff(self.num_days_from_ce(), rhs.num_days_from_ce()) as u64)
+    }
+
     /// Returns the number of whole years from the given `base` until `self`.
     ///
     /// # Errors

src/traits.rs

@@ -1,4 +1,4 @@
-use crate::{Days, IsoWeek, Month, Weekday};
+use crate::{IsoWeek, Month, Weekday};
 
 /// The common set of methods for date component.
 ///
@@ -277,12 +277,6 @@ pub trait Datelike: Sized {
         // know it is in range, and the result will never be `None`.
         month.num_days(self.year()).unwrap()
     }
-
-    /// Get the difference in days between the two days,
-    /// ignoring the time component
-    fn days_between(&self, other: impl Datelike) -> Days {
-        Days::new(i32::abs_diff(self.num_days_from_ce(), other.num_days_from_ce()).into())
-    }
 }
 
 /// The common set of methods for time component.