vendor/chrono-0.4.38/src/date.rs - toolchain/rustc - Git at Google

 // This is a part of Chrono.
 // See README.md and LICENSE.txt for details.

 //! ISO 8601 calendar date with time zone.
 #![allow(deprecated)]

 #[cfg(feature = "alloc")]
 use core::borrow::Borrow;
 use core::cmp::Ordering;
 use core::ops::{Add, AddAssign, Sub, SubAssign};
 use core::{fmt, hash};

 #[cfg(feature = "rkyv")]
 use rkyv::{Archive, Deserialize, Serialize};

 #[cfg(all(feature = "unstable-locales", feature = "alloc"))]
 use crate::format::Locale;
 #[cfg(feature = "alloc")]
 use crate::format::{DelayedFormat, Item, StrftimeItems};
 use crate::naive::{IsoWeek, NaiveDate, NaiveTime};
 use crate::offset::{TimeZone, Utc};
 use crate::{DateTime, Datelike, TimeDelta, Weekday};

 /// ISO 8601 calendar date with time zone.
 ///
 /// You almost certainly want to be using a [`NaiveDate`] instead of this type.
 ///
 /// This type primarily exists to aid in the construction of DateTimes that
 /// have a timezone by way of the [`TimeZone`] datelike constructors (e.g.
 /// [`TimeZone::ymd`]).
 ///
 /// This type should be considered ambiguous at best, due to the inherent lack
 /// of precision required for the time zone resolution.
 ///
 /// There are some guarantees on the usage of `Date<Tz>`:
 ///
 /// - If properly constructed via [`TimeZone::ymd`] and others without an error,
 ///   the corresponding local date should exist for at least a moment.
 ///   (It may still have a gap from the offset changes.)
 ///
 /// - The `TimeZone` is free to assign *any* [`Offset`](crate::offset::Offset) to the
 ///   local date, as long as that offset did occur in given day.
 ///
 ///   For example, if `2015-03-08T01:59-08:00` is followed by `2015-03-08T03:00-07:00`,
 ///   it may produce either `2015-03-08-08:00` or `2015-03-08-07:00`
 ///   but *not* `2015-03-08+00:00` and others.
 ///
 /// - Once constructed as a full `DateTime`, [`DateTime::date`] and other associated
 ///   methods should return those for the original `Date`. For example, if `dt =
 ///   tz.ymd_opt(y,m,d).unwrap().hms(h,n,s)` were valid, `dt.date() == tz.ymd_opt(y,m,d).unwrap()`.
 ///
 /// - The date is timezone-agnostic up to one day (i.e. practically always),
 ///   so the local date and UTC date should be equal for most cases
 ///   even though the raw calculation between `NaiveDate` and `TimeDelta` may not.
 #[deprecated(since = "0.4.23", note = "Use `NaiveDate` or `DateTime<Tz>` instead")]
 #[derive(Clone)]
 #[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
 pub struct Date<Tz: TimeZone> {
     date: NaiveDate,
     offset: Tz::Offset,
 }

 /// The minimum possible `Date`.
 #[allow(deprecated)]
 #[deprecated(since = "0.4.20", note = "Use Date::MIN_UTC instead")]
 pub const MIN_DATE: Date<Utc> = Date::<Utc>::MIN_UTC;
 /// The maximum possible `Date`.
 #[allow(deprecated)]
 #[deprecated(since = "0.4.20", note = "Use Date::MAX_UTC instead")]
 pub const MAX_DATE: Date<Utc> = Date::<Utc>::MAX_UTC;

 impl<Tz: TimeZone> Date<Tz> {
     /// Makes a new `Date` with given *UTC* date and offset.
     /// The local date should be constructed via the `TimeZone` trait.
     #[inline]
     #[must_use]
     pub fn from_utc(date: NaiveDate, offset: Tz::Offset) -> Date<Tz> {
         Date { date, offset }
     }

     /// Makes a new `DateTime` from the current date and given `NaiveTime`.
     /// The offset in the current date is preserved.
     ///
     /// Returns `None` on invalid datetime.
     #[inline]
     #[must_use]
     pub fn and_time(&self, time: NaiveTime) -> Option<DateTime<Tz>> {
         let localdt = self.naive_local().and_time(time);
         self.timezone().from_local_datetime(&localdt).single()
     }

     /// Makes a new `DateTime` from the current date, hour, minute and second.
     /// The offset in the current date is preserved.
     ///
     /// Panics on invalid hour, minute and/or second.
     #[deprecated(since = "0.4.23", note = "Use and_hms_opt() instead")]
     #[inline]
     #[must_use]
     pub fn and_hms(&self, hour: u32, min: u32, sec: u32) -> DateTime<Tz> {
         self.and_hms_opt(hour, min, sec).expect("invalid time")
     }

     /// Makes a new `DateTime` from the current date, hour, minute and second.
     /// The offset in the current date is preserved.
     ///
     /// Returns `None` on invalid hour, minute and/or second.
     #[inline]
     #[must_use]
     pub fn and_hms_opt(&self, hour: u32, min: u32, sec: u32) -> Option<DateTime<Tz>> {
         NaiveTime::from_hms_opt(hour, min, sec).and_then(|time| self.and_time(time))
     }

     /// Makes a new `DateTime` from the current date, hour, minute, second and millisecond.
     /// The millisecond part can exceed 1,000 in order to represent the leap second.
     /// The offset in the current date is preserved.
     ///
     /// Panics on invalid hour, minute, second and/or millisecond.
     #[deprecated(since = "0.4.23", note = "Use and_hms_milli_opt() instead")]
     #[inline]
     #[must_use]
     pub fn and_hms_milli(&self, hour: u32, min: u32, sec: u32, milli: u32) -> DateTime<Tz> {
         self.and_hms_milli_opt(hour, min, sec, milli).expect("invalid time")
     }

     /// Makes a new `DateTime` from the current date, hour, minute, second and millisecond.
     /// The millisecond part can exceed 1,000 in order to represent the leap second.
     /// The offset in the current date is preserved.
     ///
     /// Returns `None` on invalid hour, minute, second and/or millisecond.
     #[inline]
     #[must_use]
     pub fn and_hms_milli_opt(
         &self,
         hour: u32,
         min: u32,
         sec: u32,
         milli: u32,
     ) -> Option<DateTime<Tz>> {
         NaiveTime::from_hms_milli_opt(hour, min, sec, milli).and_then(|time| self.and_time(time))
     }

     /// Makes a new `DateTime` from the current date, hour, minute, second and microsecond.
     /// The microsecond part can exceed 1,000,000 in order to represent the leap second.
     /// The offset in the current date is preserved.
     ///
     /// Panics on invalid hour, minute, second and/or microsecond.
     #[deprecated(since = "0.4.23", note = "Use and_hms_micro_opt() instead")]
     #[inline]
     #[must_use]
     pub fn and_hms_micro(&self, hour: u32, min: u32, sec: u32, micro: u32) -> DateTime<Tz> {
         self.and_hms_micro_opt(hour, min, sec, micro).expect("invalid time")
     }

     /// Makes a new `DateTime` from the current date, hour, minute, second and microsecond.
     /// The microsecond part can exceed 1,000,000 in order to represent the leap second.
     /// The offset in the current date is preserved.
     ///
     /// Returns `None` on invalid hour, minute, second and/or microsecond.
     #[inline]
     #[must_use]
     pub fn and_hms_micro_opt(
         &self,
         hour: u32,
         min: u32,
         sec: u32,
         micro: u32,
     ) -> Option<DateTime<Tz>> {
         NaiveTime::from_hms_micro_opt(hour, min, sec, micro).and_then(|time| self.and_time(time))
     }

     /// Makes a new `DateTime` from the current date, hour, minute, second and nanosecond.
     /// The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.
     /// The offset in the current date is preserved.
     ///
     /// Panics on invalid hour, minute, second and/or nanosecond.
     #[deprecated(since = "0.4.23", note = "Use and_hms_nano_opt() instead")]
     #[inline]
     #[must_use]
     pub fn and_hms_nano(&self, hour: u32, min: u32, sec: u32, nano: u32) -> DateTime<Tz> {
         self.and_hms_nano_opt(hour, min, sec, nano).expect("invalid time")
     }

     /// Makes a new `DateTime` from the current date, hour, minute, second and nanosecond.
     /// The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.
     /// The offset in the current date is preserved.
     ///
     /// Returns `None` on invalid hour, minute, second and/or nanosecond.
     #[inline]
     #[must_use]
     pub fn and_hms_nano_opt(
         &self,
         hour: u32,
         min: u32,
         sec: u32,
         nano: u32,
     ) -> Option<DateTime<Tz>> {
         NaiveTime::from_hms_nano_opt(hour, min, sec, nano).and_then(|time| self.and_time(time))
     }

     /// Makes a new `Date` for the next date.
     ///
     /// Panics when `self` is the last representable date.
     #[deprecated(since = "0.4.23", note = "Use succ_opt() instead")]
     #[inline]
     #[must_use]
     pub fn succ(&self) -> Date<Tz> {
         self.succ_opt().expect("out of bound")
     }

     /// Makes a new `Date` for the next date.
     ///
     /// Returns `None` when `self` is the last representable date.
     #[inline]
     #[must_use]
     pub fn succ_opt(&self) -> Option<Date<Tz>> {
         self.date.succ_opt().map(|date| Date::from_utc(date, self.offset.clone()))
     }

     /// Makes a new `Date` for the prior date.
     ///
     /// Panics when `self` is the first representable date.
     #[deprecated(since = "0.4.23", note = "Use pred_opt() instead")]
     #[inline]
     #[must_use]
     pub fn pred(&self) -> Date<Tz> {
         self.pred_opt().expect("out of bound")
     }

     /// Makes a new `Date` for the prior date.
     ///
     /// Returns `None` when `self` is the first representable date.
     #[inline]
     #[must_use]
     pub fn pred_opt(&self) -> Option<Date<Tz>> {
         self.date.pred_opt().map(|date| Date::from_utc(date, self.offset.clone()))
     }

     /// Retrieves an associated offset from UTC.
     #[inline]
     #[must_use]
     pub fn offset(&self) -> &Tz::Offset {
         &self.offset
     }

     /// Retrieves an associated time zone.
     #[inline]
     #[must_use]
     pub fn timezone(&self) -> Tz {
         TimeZone::from_offset(&self.offset)
     }

     /// Changes the associated time zone.
     /// This does not change the actual `Date` (but will change the string representation).
     #[inline]
     #[must_use]
     pub fn with_timezone<Tz2: TimeZone>(&self, tz: &Tz2) -> Date<Tz2> {
         tz.from_utc_date(&self.date)
     }

     /// Adds given `TimeDelta` to the current date.
     ///
     /// Returns `None` when it will result in overflow.
     #[inline]
     #[must_use]
     pub fn checked_add_signed(self, rhs: TimeDelta) -> Option<Date<Tz>> {
         let date = self.date.checked_add_signed(rhs)?;
         Some(Date { date, offset: self.offset })
     }

     /// Subtracts given `TimeDelta` from the current date.
     ///
     /// Returns `None` when it will result in overflow.
     #[inline]
     #[must_use]
     pub fn checked_sub_signed(self, rhs: TimeDelta) -> Option<Date<Tz>> {
         let date = self.date.checked_sub_signed(rhs)?;
         Some(Date { date, offset: self.offset })
     }

     /// Subtracts another `Date` from the current date.
     /// Returns a `TimeDelta` of integral numbers.
     ///
     /// This does not overflow or underflow at all,
     /// as all possible output fits in the range of `TimeDelta`.
     #[inline]
     #[must_use]
     pub fn signed_duration_since<Tz2: TimeZone>(self, rhs: Date<Tz2>) -> TimeDelta {
         self.date.signed_duration_since(rhs.date)
     }

     /// Returns a view to the naive UTC date.
     #[inline]
     #[must_use]
     pub fn naive_utc(&self) -> NaiveDate {
         self.date
     }

     /// Returns a view to the naive local date.
     ///
     /// This is technically the same as [`naive_utc`](#method.naive_utc)
     /// because the offset is restricted to never exceed one day,
     /// but provided for the consistency.
     #[inline]
     #[must_use]
     pub fn naive_local(&self) -> NaiveDate {
         self.date
     }

     /// Returns the number of whole years from the given `base` until `self`.
     #[must_use]
     pub fn years_since(&self, base: Self) -> Option<u32> {
         self.date.years_since(base.date)
     }

     /// The minimum possible `Date`.
     pub const MIN_UTC: Date<Utc> = Date { date: NaiveDate::MIN, offset: Utc };
     /// The maximum possible `Date`.
     pub const MAX_UTC: Date<Utc> = Date { date: NaiveDate::MAX, offset: Utc };
 }

 /// Maps the local date to other date with given conversion function.
 fn map_local<Tz: TimeZone, F>(d: &Date<Tz>, mut f: F) -> Option<Date<Tz>>
 where
     F: FnMut(NaiveDate) -> Option<NaiveDate>,
 {
     f(d.naive_local()).and_then(|date| d.timezone().from_local_date(&date).single())
 }

 impl<Tz: TimeZone> Date<Tz>
 where
     Tz::Offset: fmt::Display,
 {
     /// Formats the date with the specified formatting items.
     #[cfg(feature = "alloc")]
     #[inline]
     #[must_use]
     pub fn format_with_items<'a, I, B>(&self, items: I) -> DelayedFormat<I>
     where
         I: Iterator<Item = B> + Clone,
         B: Borrow<Item<'a>>,
     {
         DelayedFormat::new_with_offset(Some(self.naive_local()), None, &self.offset, items)
     }

     /// Formats the date with the specified format string.
     /// See the [`crate::format::strftime`] module
     /// on the supported escape sequences.
     #[cfg(feature = "alloc")]
     #[inline]
     #[must_use]
     pub fn format<'a>(&self, fmt: &'a str) -> DelayedFormat<StrftimeItems<'a>> {
         self.format_with_items(StrftimeItems::new(fmt))
     }

     /// Formats the date with the specified formatting items and locale.
     #[cfg(all(feature = "unstable-locales", feature = "alloc"))]
     #[inline]
     #[must_use]
     pub fn format_localized_with_items<'a, I, B>(
         &self,
         items: I,
         locale: Locale,
     ) -> DelayedFormat<I>
     where
         I: Iterator<Item = B> + Clone,
         B: Borrow<Item<'a>>,
     {
         DelayedFormat::new_with_offset_and_locale(
             Some(self.naive_local()),
             None,
             &self.offset,
             items,
             locale,
         )
     }

     /// Formats the date with the specified format string and locale.
     /// See the [`crate::format::strftime`] module
     /// on the supported escape sequences.
     #[cfg(all(feature = "unstable-locales", feature = "alloc"))]
     #[inline]
     #[must_use]
     pub fn format_localized<'a>(
         &self,
         fmt: &'a str,
         locale: Locale,
     ) -> DelayedFormat<StrftimeItems<'a>> {
         self.format_localized_with_items(StrftimeItems::new_with_locale(fmt, locale), locale)
     }
 }

 impl<Tz: TimeZone> Datelike for Date<Tz> {
     #[inline]
     fn year(&self) -> i32 {
         self.naive_local().year()
     }
     #[inline]
     fn month(&self) -> u32 {
         self.naive_local().month()
     }
     #[inline]
     fn month0(&self) -> u32 {
         self.naive_local().month0()
     }
     #[inline]
     fn day(&self) -> u32 {
         self.naive_local().day()
     }
     #[inline]
     fn day0(&self) -> u32 {
         self.naive_local().day0()
     }
     #[inline]
     fn ordinal(&self) -> u32 {
         self.naive_local().ordinal()
     }
     #[inline]
     fn ordinal0(&self) -> u32 {
         self.naive_local().ordinal0()
     }
     #[inline]
     fn weekday(&self) -> Weekday {
         self.naive_local().weekday()
     }
     #[inline]
     fn iso_week(&self) -> IsoWeek {
         self.naive_local().iso_week()
     }

     #[inline]
     fn with_year(&self, year: i32) -> Option<Date<Tz>> {
         map_local(self, |date| date.with_year(year))
     }

     #[inline]
     fn with_month(&self, month: u32) -> Option<Date<Tz>> {
         map_local(self, |date| date.with_month(month))
     }

     #[inline]
     fn with_month0(&self, month0: u32) -> Option<Date<Tz>> {
         map_local(self, |date| date.with_month0(month0))
     }

     #[inline]
     fn with_day(&self, day: u32) -> Option<Date<Tz>> {
         map_local(self, |date| date.with_day(day))
     }

     #[inline]
     fn with_day0(&self, day0: u32) -> Option<Date<Tz>> {
         map_local(self, |date| date.with_day0(day0))
     }

     #[inline]
     fn with_ordinal(&self, ordinal: u32) -> Option<Date<Tz>> {
         map_local(self, |date| date.with_ordinal(ordinal))
     }

     #[inline]
     fn with_ordinal0(&self, ordinal0: u32) -> Option<Date<Tz>> {
         map_local(self, |date| date.with_ordinal0(ordinal0))
     }
 }

 // we need them as automatic impls cannot handle associated types
 impl<Tz: TimeZone> Copy for Date<Tz> where <Tz as TimeZone>::Offset: Copy {}
 unsafe impl<Tz: TimeZone> Send for Date<Tz> where <Tz as TimeZone>::Offset: Send {}

 impl<Tz: TimeZone, Tz2: TimeZone> PartialEq<Date<Tz2>> for Date<Tz> {
     fn eq(&self, other: &Date<Tz2>) -> bool {
         self.date == other.date
     }
 }

 impl<Tz: TimeZone> Eq for Date<Tz> {}

 impl<Tz: TimeZone> PartialOrd for Date<Tz> {
     fn partial_cmp(&self, other: &Date<Tz>) -> Option<Ordering> {
         Some(self.cmp(other))
     }
 }

 impl<Tz: TimeZone> Ord for Date<Tz> {
     fn cmp(&self, other: &Date<Tz>) -> Ordering {
         self.date.cmp(&other.date)
     }
 }

 impl<Tz: TimeZone> hash::Hash for Date<Tz> {
     fn hash<H: hash::Hasher>(&self, state: &mut H) {
         self.date.hash(state)
     }
 }

 impl<Tz: TimeZone> Add<TimeDelta> for Date<Tz> {
     type Output = Date<Tz>;

     #[inline]
     fn add(self, rhs: TimeDelta) -> Date<Tz> {
         self.checked_add_signed(rhs).expect("`Date + TimeDelta` overflowed")
     }
 }

 impl<Tz: TimeZone> AddAssign<TimeDelta> for Date<Tz> {
     #[inline]
     fn add_assign(&mut self, rhs: TimeDelta) {
         self.date = self.date.checked_add_signed(rhs).expect("`Date + TimeDelta` overflowed");
     }
 }

 impl<Tz: TimeZone> Sub<TimeDelta> for Date<Tz> {
     type Output = Date<Tz>;

     #[inline]
     fn sub(self, rhs: TimeDelta) -> Date<Tz> {
         self.checked_sub_signed(rhs).expect("`Date - TimeDelta` overflowed")
     }
 }

 impl<Tz: TimeZone> SubAssign<TimeDelta> for Date<Tz> {
     #[inline]
     fn sub_assign(&mut self, rhs: TimeDelta) {
         self.date = self.date.checked_sub_signed(rhs).expect("`Date - TimeDelta` overflowed");
     }
 }

 impl<Tz: TimeZone> Sub<Date<Tz>> for Date<Tz> {
     type Output = TimeDelta;

     #[inline]
     fn sub(self, rhs: Date<Tz>) -> TimeDelta {
         self.signed_duration_since(rhs)
     }
 }

 impl<Tz: TimeZone> fmt::Debug for Date<Tz> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         self.naive_local().fmt(f)?;
         self.offset.fmt(f)
     }
 }

 impl<Tz: TimeZone> fmt::Display for Date<Tz>
 where
     Tz::Offset: fmt::Display,
 {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         self.naive_local().fmt(f)?;
         self.offset.fmt(f)
     }
 }

 // Note that implementation of Arbitrary cannot be automatically derived for Date<Tz>, due to
 // the nontrivial bound <Tz as TimeZone>::Offset: Arbitrary.
 #[cfg(all(feature = "arbitrary", feature = "std"))]
 impl<'a, Tz> arbitrary::Arbitrary<'a> for Date<Tz>
 where
     Tz: TimeZone,
     <Tz as TimeZone>::Offset: arbitrary::Arbitrary<'a>,
 {
     fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Date<Tz>> {
         let date = NaiveDate::arbitrary(u)?;
         let offset = <Tz as TimeZone>::Offset::arbitrary(u)?;
         Ok(Date::from_utc(date, offset))
     }
 }

 #[cfg(test)]
 mod tests {
     use super::Date;

     use crate::{FixedOffset, NaiveDate, TimeDelta, Utc};

     #[cfg(feature = "clock")]
     use crate::offset::{Local, TimeZone};

     #[test]
     #[cfg(feature = "clock")]
     fn test_years_elapsed() {
         const WEEKS_PER_YEAR: f32 = 52.1775;

         // This is always at least one year because 1 year = 52.1775 weeks.
         let one_year_ago = Utc::today() - TimeDelta::weeks((WEEKS_PER_YEAR * 1.5).ceil() as i64);
         // A bit more than 2 years.
         let two_year_ago = Utc::today() - TimeDelta::weeks((WEEKS_PER_YEAR * 2.5).ceil() as i64);

         assert_eq!(Utc::today().years_since(one_year_ago), Some(1));
         assert_eq!(Utc::today().years_since(two_year_ago), Some(2));

         // If the given DateTime is later than now, the function will always return 0.
         let future = Utc::today() + TimeDelta::weeks(12);
         assert_eq!(Utc::today().years_since(future), None);
     }

     #[test]
     fn test_date_add_assign() {
         let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();
         let date = Date::<Utc>::from_utc(naivedate, Utc);
         let mut date_add = date;

         date_add += TimeDelta::days(5);
         assert_eq!(date_add, date + TimeDelta::days(5));

         let timezone = FixedOffset::east_opt(60 * 60).unwrap();
         let date = date.with_timezone(&timezone);
         let date_add = date_add.with_timezone(&timezone);

         assert_eq!(date_add, date + TimeDelta::days(5));

         let timezone = FixedOffset::west_opt(2 * 60 * 60).unwrap();
         let date = date.with_timezone(&timezone);
         let date_add = date_add.with_timezone(&timezone);

         assert_eq!(date_add, date + TimeDelta::days(5));
     }

     #[test]
     #[cfg(feature = "clock")]
     fn test_date_add_assign_local() {
         let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();

         let date = Local.from_utc_date(&naivedate);
         let mut date_add = date;

         date_add += TimeDelta::days(5);
         assert_eq!(date_add, date + TimeDelta::days(5));
     }

     #[test]
     fn test_date_sub_assign() {
         let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();
         let date = Date::<Utc>::from_utc(naivedate, Utc);
         let mut date_sub = date;

         date_sub -= TimeDelta::days(5);
         assert_eq!(date_sub, date - TimeDelta::days(5));

         let timezone = FixedOffset::east_opt(60 * 60).unwrap();
         let date = date.with_timezone(&timezone);
         let date_sub = date_sub.with_timezone(&timezone);

         assert_eq!(date_sub, date - TimeDelta::days(5));

         let timezone = FixedOffset::west_opt(2 * 60 * 60).unwrap();
         let date = date.with_timezone(&timezone);
         let date_sub = date_sub.with_timezone(&timezone);

         assert_eq!(date_sub, date - TimeDelta::days(5));
     }

     #[test]
     #[cfg(feature = "clock")]
     fn test_date_sub_assign_local() {
         let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();

         let date = Local.from_utc_date(&naivedate);
         let mut date_sub = date;

         date_sub -= TimeDelta::days(5);
         assert_eq!(date_sub, date - TimeDelta::days(5));
     }
 }
	// This is a part of Chrono.
	// See README.md and LICENSE.txt for details.

	//! ISO 8601 calendar date with time zone.
	#![allow(deprecated)]

	#[cfg(feature = "alloc")]
	use core::borrow::Borrow;
	use core::cmp::Ordering;
	use core::ops::{Add, AddAssign, Sub, SubAssign};
	use core::{fmt, hash};

	#[cfg(feature = "rkyv")]
	use rkyv::{Archive, Deserialize, Serialize};

	#[cfg(all(feature = "unstable-locales", feature = "alloc"))]
	use crate::format::Locale;
	#[cfg(feature = "alloc")]
	use crate::format::{DelayedFormat, Item, StrftimeItems};
	use crate::naive::{IsoWeek, NaiveDate, NaiveTime};
	use crate::offset::{TimeZone, Utc};
	use crate::{DateTime, Datelike, TimeDelta, Weekday};

	/// ISO 8601 calendar date with time zone.
	///
	/// You almost certainly want to be using a [`NaiveDate`] instead of this type.
	///
	/// This type primarily exists to aid in the construction of DateTimes that
	/// have a timezone by way of the [`TimeZone`] datelike constructors (e.g.
	/// [`TimeZone::ymd`]).
	///
	/// This type should be considered ambiguous at best, due to the inherent lack
	/// of precision required for the time zone resolution.
	///
	/// There are some guarantees on the usage of `Date<Tz>`:
	///
	/// - If properly constructed via [`TimeZone::ymd`] and others without an error,
	/// the corresponding local date should exist for at least a moment.
	/// (It may still have a gap from the offset changes.)
	///
	/// - The `TimeZone` is free to assign any [`Offset`](crate::offset::Offset) to the
	/// local date, as long as that offset did occur in given day.
	///
	/// For example, if `2015-03-08T01:59-08:00` is followed by `2015-03-08T03:00-07:00`,
	/// it may produce either `2015-03-08-08:00` or `2015-03-08-07:00`
	/// but not `2015-03-08+00:00` and others.
	///
	/// - Once constructed as a full `DateTime`, [`DateTime::date`] and other associated
	/// methods should return those for the original `Date`. For example, if `dt =
	/// tz.ymd_opt(y,m,d).unwrap().hms(h,n,s)` were valid, `dt.date() == tz.ymd_opt(y,m,d).unwrap()`.
	///
	/// - The date is timezone-agnostic up to one day (i.e. practically always),
	/// so the local date and UTC date should be equal for most cases
	/// even though the raw calculation between `NaiveDate` and `TimeDelta` may not.
	#[deprecated(since = "0.4.23", note = "Use `NaiveDate` or `DateTime<Tz>` instead")]
	#[derive(Clone)]
	#[cfg_attr(feature = "rkyv", derive(Archive, Deserialize, Serialize))]
	pub struct Date<Tz: TimeZone> {
	date: NaiveDate,
	offset: Tz::Offset,
	}

	/// The minimum possible `Date`.
	#[allow(deprecated)]
	#[deprecated(since = "0.4.20", note = "Use Date::MIN_UTC instead")]
	pub const MIN_DATE: Date<Utc> = Date::<Utc>::MIN_UTC;
	/// The maximum possible `Date`.
	#[allow(deprecated)]
	#[deprecated(since = "0.4.20", note = "Use Date::MAX_UTC instead")]
	pub const MAX_DATE: Date<Utc> = Date::<Utc>::MAX_UTC;

	impl<Tz: TimeZone> Date<Tz> {
	/// Makes a new `Date` with given UTC date and offset.
	/// The local date should be constructed via the `TimeZone` trait.
	#[inline]
	#[must_use]
	pub fn from_utc(date: NaiveDate, offset: Tz::Offset) -> Date<Tz> {
	Date { date, offset }
	}

	/// Makes a new `DateTime` from the current date and given `NaiveTime`.
	/// The offset in the current date is preserved.
	///
	/// Returns `None` on invalid datetime.
	#[inline]
	#[must_use]
	pub fn and_time(&self, time: NaiveTime) -> Option<DateTime<Tz>> {
	let localdt = self.naive_local().and_time(time);
	self.timezone().from_local_datetime(&localdt).single()
	}

	/// Makes a new `DateTime` from the current date, hour, minute and second.
	/// The offset in the current date is preserved.
	///
	/// Panics on invalid hour, minute and/or second.
	#[deprecated(since = "0.4.23", note = "Use and_hms_opt() instead")]
	#[inline]
	#[must_use]
	pub fn and_hms(&self, hour: u32, min: u32, sec: u32) -> DateTime<Tz> {
	self.and_hms_opt(hour, min, sec).expect("invalid time")
	}

	/// Makes a new `DateTime` from the current date, hour, minute and second.
	/// The offset in the current date is preserved.
	///
	/// Returns `None` on invalid hour, minute and/or second.
	#[inline]
	#[must_use]
	pub fn and_hms_opt(&self, hour: u32, min: u32, sec: u32) -> Option<DateTime<Tz>> {
	NaiveTime::from_hms_opt(hour, min, sec).and_then(\|time\| self.and_time(time))
	}

	/// Makes a new `DateTime` from the current date, hour, minute, second and millisecond.
	/// The millisecond part can exceed 1,000 in order to represent the leap second.
	/// The offset in the current date is preserved.
	///
	/// Panics on invalid hour, minute, second and/or millisecond.
	#[deprecated(since = "0.4.23", note = "Use and_hms_milli_opt() instead")]
	#[inline]
	#[must_use]
	pub fn and_hms_milli(&self, hour: u32, min: u32, sec: u32, milli: u32) -> DateTime<Tz> {
	self.and_hms_milli_opt(hour, min, sec, milli).expect("invalid time")
	}

	/// Makes a new `DateTime` from the current date, hour, minute, second and millisecond.
	/// The millisecond part can exceed 1,000 in order to represent the leap second.
	/// The offset in the current date is preserved.
	///
	/// Returns `None` on invalid hour, minute, second and/or millisecond.
	#[inline]
	#[must_use]
	pub fn and_hms_milli_opt(
	&self,
	hour: u32,
	min: u32,
	sec: u32,
	milli: u32,
	) -> Option<DateTime<Tz>> {
	NaiveTime::from_hms_milli_opt(hour, min, sec, milli).and_then(\|time\| self.and_time(time))
	}

	/// Makes a new `DateTime` from the current date, hour, minute, second and microsecond.
	/// The microsecond part can exceed 1,000,000 in order to represent the leap second.
	/// The offset in the current date is preserved.
	///
	/// Panics on invalid hour, minute, second and/or microsecond.
	#[deprecated(since = "0.4.23", note = "Use and_hms_micro_opt() instead")]
	#[inline]
	#[must_use]
	pub fn and_hms_micro(&self, hour: u32, min: u32, sec: u32, micro: u32) -> DateTime<Tz> {
	self.and_hms_micro_opt(hour, min, sec, micro).expect("invalid time")
	}

	/// Makes a new `DateTime` from the current date, hour, minute, second and microsecond.
	/// The microsecond part can exceed 1,000,000 in order to represent the leap second.
	/// The offset in the current date is preserved.
	///
	/// Returns `None` on invalid hour, minute, second and/or microsecond.
	#[inline]
	#[must_use]
	pub fn and_hms_micro_opt(
	&self,
	hour: u32,
	min: u32,
	sec: u32,
	micro: u32,
	) -> Option<DateTime<Tz>> {
	NaiveTime::from_hms_micro_opt(hour, min, sec, micro).and_then(\|time\| self.and_time(time))
	}

	/// Makes a new `DateTime` from the current date, hour, minute, second and nanosecond.
	/// The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.
	/// The offset in the current date is preserved.
	///
	/// Panics on invalid hour, minute, second and/or nanosecond.
	#[deprecated(since = "0.4.23", note = "Use and_hms_nano_opt() instead")]
	#[inline]
	#[must_use]
	pub fn and_hms_nano(&self, hour: u32, min: u32, sec: u32, nano: u32) -> DateTime<Tz> {
	self.and_hms_nano_opt(hour, min, sec, nano).expect("invalid time")
	}

	/// Makes a new `DateTime` from the current date, hour, minute, second and nanosecond.
	/// The nanosecond part can exceed 1,000,000,000 in order to represent the leap second.
	/// The offset in the current date is preserved.
	///
	/// Returns `None` on invalid hour, minute, second and/or nanosecond.
	#[inline]
	#[must_use]
	pub fn and_hms_nano_opt(
	&self,
	hour: u32,
	min: u32,
	sec: u32,
	nano: u32,
	) -> Option<DateTime<Tz>> {
	NaiveTime::from_hms_nano_opt(hour, min, sec, nano).and_then(\|time\| self.and_time(time))
	}

	/// Makes a new `Date` for the next date.
	///
	/// Panics when `self` is the last representable date.
	#[deprecated(since = "0.4.23", note = "Use succ_opt() instead")]
	#[inline]
	#[must_use]
	pub fn succ(&self) -> Date<Tz> {
	self.succ_opt().expect("out of bound")
	}

	/// Makes a new `Date` for the next date.
	///
	/// Returns `None` when `self` is the last representable date.
	#[inline]
	#[must_use]
	pub fn succ_opt(&self) -> Option<Date<Tz>> {
	self.date.succ_opt().map(\|date\| Date::from_utc(date, self.offset.clone()))
	}

	/// Makes a new `Date` for the prior date.
	///
	/// Panics when `self` is the first representable date.
	#[deprecated(since = "0.4.23", note = "Use pred_opt() instead")]
	#[inline]
	#[must_use]
	pub fn pred(&self) -> Date<Tz> {
	self.pred_opt().expect("out of bound")
	}

	/// Makes a new `Date` for the prior date.
	///
	/// Returns `None` when `self` is the first representable date.
	#[inline]
	#[must_use]
	pub fn pred_opt(&self) -> Option<Date<Tz>> {
	self.date.pred_opt().map(\|date\| Date::from_utc(date, self.offset.clone()))
	}

	/// Retrieves an associated offset from UTC.
	#[inline]
	#[must_use]
	pub fn offset(&self) -> &Tz::Offset {
	&self.offset
	}

	/// Retrieves an associated time zone.
	#[inline]
	#[must_use]
	pub fn timezone(&self) -> Tz {
	TimeZone::from_offset(&self.offset)
	}

	/// Changes the associated time zone.
	/// This does not change the actual `Date` (but will change the string representation).
	#[inline]
	#[must_use]
	pub fn with_timezone<Tz2: TimeZone>(&self, tz: &Tz2) -> Date<Tz2> {
	tz.from_utc_date(&self.date)
	}

	/// Adds given `TimeDelta` to the current date.
	///
	/// Returns `None` when it will result in overflow.
	#[inline]
	#[must_use]
	pub fn checked_add_signed(self, rhs: TimeDelta) -> Option<Date<Tz>> {
	let date = self.date.checked_add_signed(rhs)?;
	Some(Date { date, offset: self.offset })
	}

	/// Subtracts given `TimeDelta` from the current date.
	///
	/// Returns `None` when it will result in overflow.
	#[inline]
	#[must_use]
	pub fn checked_sub_signed(self, rhs: TimeDelta) -> Option<Date<Tz>> {
	let date = self.date.checked_sub_signed(rhs)?;
	Some(Date { date, offset: self.offset })
	}

	/// Subtracts another `Date` from the current date.
	/// Returns a `TimeDelta` of integral numbers.
	///
	/// This does not overflow or underflow at all,
	/// as all possible output fits in the range of `TimeDelta`.
	#[inline]
	#[must_use]
	pub fn signed_duration_since<Tz2: TimeZone>(self, rhs: Date<Tz2>) -> TimeDelta {
	self.date.signed_duration_since(rhs.date)
	}

	/// Returns a view to the naive UTC date.
	#[inline]
	#[must_use]
	pub fn naive_utc(&self) -> NaiveDate {
	self.date
	}

	/// Returns a view to the naive local date.
	///
	/// This is technically the same as [`naive_utc`](#method.naive_utc)
	/// because the offset is restricted to never exceed one day,
	/// but provided for the consistency.
	#[inline]
	#[must_use]
	pub fn naive_local(&self) -> NaiveDate {
	self.date
	}

	/// Returns the number of whole years from the given `base` until `self`.
	#[must_use]
	pub fn years_since(&self, base: Self) -> Option<u32> {
	self.date.years_since(base.date)
	}

	/// The minimum possible `Date`.
	pub const MIN_UTC: Date<Utc> = Date { date: NaiveDate::MIN, offset: Utc };
	/// The maximum possible `Date`.
	pub const MAX_UTC: Date<Utc> = Date { date: NaiveDate::MAX, offset: Utc };
	}

	/// Maps the local date to other date with given conversion function.
	fn map_local<Tz: TimeZone, F>(d: &Date<Tz>, mut f: F) -> Option<Date<Tz>>
	where
	F: FnMut(NaiveDate) -> Option<NaiveDate>,
	{
	f(d.naive_local()).and_then(\|date\| d.timezone().from_local_date(&date).single())
	}

	impl<Tz: TimeZone> Date<Tz>
	where
	Tz::Offset: fmt::Display,
	{
	/// Formats the date with the specified formatting items.
	#[cfg(feature = "alloc")]
	#[inline]
	#[must_use]
	pub fn format_with_items<'a, I, B>(&self, items: I) -> DelayedFormat<I>
	where
	I: Iterator<Item = B> + Clone,
	B: Borrow<Item<'a>>,
	{
	DelayedFormat::new_with_offset(Some(self.naive_local()), None, &self.offset, items)
	}

	/// Formats the date with the specified format string.
	/// See the [`crate::format::strftime`] module
	/// on the supported escape sequences.
	#[cfg(feature = "alloc")]
	#[inline]
	#[must_use]
	pub fn format<'a>(&self, fmt: &'a str) -> DelayedFormat<StrftimeItems<'a>> {
	self.format_with_items(StrftimeItems::new(fmt))
	}

	/// Formats the date with the specified formatting items and locale.
	#[cfg(all(feature = "unstable-locales", feature = "alloc"))]
	#[inline]
	#[must_use]
	pub fn format_localized_with_items<'a, I, B>(
	&self,
	items: I,
	locale: Locale,
	) -> DelayedFormat<I>
	where
	I: Iterator<Item = B> + Clone,
	B: Borrow<Item<'a>>,
	{
	DelayedFormat::new_with_offset_and_locale(
	Some(self.naive_local()),
	None,
	&self.offset,
	items,
	locale,
	)
	}

	/// Formats the date with the specified format string and locale.
	/// See the [`crate::format::strftime`] module
	/// on the supported escape sequences.
	#[cfg(all(feature = "unstable-locales", feature = "alloc"))]
	#[inline]
	#[must_use]
	pub fn format_localized<'a>(
	&self,
	fmt: &'a str,
	locale: Locale,
	) -> DelayedFormat<StrftimeItems<'a>> {
	self.format_localized_with_items(StrftimeItems::new_with_locale(fmt, locale), locale)
	}
	}

	impl<Tz: TimeZone> Datelike for Date<Tz> {
	#[inline]
	fn year(&self) -> i32 {
	self.naive_local().year()
	}
	#[inline]
	fn month(&self) -> u32 {
	self.naive_local().month()
	}
	#[inline]
	fn month0(&self) -> u32 {
	self.naive_local().month0()
	}
	#[inline]
	fn day(&self) -> u32 {
	self.naive_local().day()
	}
	#[inline]
	fn day0(&self) -> u32 {
	self.naive_local().day0()
	}
	#[inline]
	fn ordinal(&self) -> u32 {
	self.naive_local().ordinal()
	}
	#[inline]
	fn ordinal0(&self) -> u32 {
	self.naive_local().ordinal0()
	}
	#[inline]
	fn weekday(&self) -> Weekday {
	self.naive_local().weekday()
	}
	#[inline]
	fn iso_week(&self) -> IsoWeek {
	self.naive_local().iso_week()
	}

	#[inline]
	fn with_year(&self, year: i32) -> Option<Date<Tz>> {
	map_local(self, \|date\| date.with_year(year))
	}

	#[inline]
	fn with_month(&self, month: u32) -> Option<Date<Tz>> {
	map_local(self, \|date\| date.with_month(month))
	}

	#[inline]
	fn with_month0(&self, month0: u32) -> Option<Date<Tz>> {
	map_local(self, \|date\| date.with_month0(month0))
	}

	#[inline]
	fn with_day(&self, day: u32) -> Option<Date<Tz>> {
	map_local(self, \|date\| date.with_day(day))
	}

	#[inline]
	fn with_day0(&self, day0: u32) -> Option<Date<Tz>> {
	map_local(self, \|date\| date.with_day0(day0))
	}

	#[inline]
	fn with_ordinal(&self, ordinal: u32) -> Option<Date<Tz>> {
	map_local(self, \|date\| date.with_ordinal(ordinal))
	}

	#[inline]
	fn with_ordinal0(&self, ordinal0: u32) -> Option<Date<Tz>> {
	map_local(self, \|date\| date.with_ordinal0(ordinal0))
	}
	}

	// we need them as automatic impls cannot handle associated types
	impl<Tz: TimeZone> Copy for Date<Tz> where <Tz as TimeZone>::Offset: Copy {}
	unsafe impl<Tz: TimeZone> Send for Date<Tz> where <Tz as TimeZone>::Offset: Send {}

	impl<Tz: TimeZone, Tz2: TimeZone> PartialEq<Date<Tz2>> for Date<Tz> {
	fn eq(&self, other: &Date<Tz2>) -> bool {
	self.date == other.date
	}
	}

	impl<Tz: TimeZone> Eq for Date<Tz> {}

	impl<Tz: TimeZone> PartialOrd for Date<Tz> {
	fn partial_cmp(&self, other: &Date<Tz>) -> Option<Ordering> {
	Some(self.cmp(other))
	}
	}

	impl<Tz: TimeZone> Ord for Date<Tz> {
	fn cmp(&self, other: &Date<Tz>) -> Ordering {
	self.date.cmp(&other.date)
	}
	}

	impl<Tz: TimeZone> hash::Hash for Date<Tz> {
	fn hash<H: hash::Hasher>(&self, state: &mut H) {
	self.date.hash(state)
	}
	}

	impl<Tz: TimeZone> Add<TimeDelta> for Date<Tz> {
	type Output = Date<Tz>;

	#[inline]
	fn add(self, rhs: TimeDelta) -> Date<Tz> {
	self.checked_add_signed(rhs).expect("`Date + TimeDelta` overflowed")
	}
	}

	impl<Tz: TimeZone> AddAssign<TimeDelta> for Date<Tz> {
	#[inline]
	fn add_assign(&mut self, rhs: TimeDelta) {
	self.date = self.date.checked_add_signed(rhs).expect("`Date + TimeDelta` overflowed");
	}
	}

	impl<Tz: TimeZone> Sub<TimeDelta> for Date<Tz> {
	type Output = Date<Tz>;

	#[inline]
	fn sub(self, rhs: TimeDelta) -> Date<Tz> {
	self.checked_sub_signed(rhs).expect("`Date - TimeDelta` overflowed")
	}
	}

	impl<Tz: TimeZone> SubAssign<TimeDelta> for Date<Tz> {
	#[inline]
	fn sub_assign(&mut self, rhs: TimeDelta) {
	self.date = self.date.checked_sub_signed(rhs).expect("`Date - TimeDelta` overflowed");
	}
	}

	impl<Tz: TimeZone> Sub<Date<Tz>> for Date<Tz> {
	type Output = TimeDelta;

	#[inline]
	fn sub(self, rhs: Date<Tz>) -> TimeDelta {
	self.signed_duration_since(rhs)
	}
	}

	impl<Tz: TimeZone> fmt::Debug for Date<Tz> {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
	self.naive_local().fmt(f)?;
	self.offset.fmt(f)
	}
	}

	impl<Tz: TimeZone> fmt::Display for Date<Tz>
	where
	Tz::Offset: fmt::Display,
	{
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
	self.naive_local().fmt(f)?;
	self.offset.fmt(f)
	}
	}

	// Note that implementation of Arbitrary cannot be automatically derived for Date<Tz>, due to
	// the nontrivial bound <Tz as TimeZone>::Offset: Arbitrary.
	#[cfg(all(feature = "arbitrary", feature = "std"))]
	impl<'a, Tz> arbitrary::Arbitrary<'a> for Date<Tz>
	where
	Tz: TimeZone,
	<Tz as TimeZone>::Offset: arbitrary::Arbitrary<'a>,
	{
	fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Date<Tz>> {
	let date = NaiveDate::arbitrary(u)?;
	let offset = <Tz as TimeZone>::Offset::arbitrary(u)?;
	Ok(Date::from_utc(date, offset))
	}
	}

	#[cfg(test)]
	mod tests {
	use super::Date;

	use crate::{FixedOffset, NaiveDate, TimeDelta, Utc};

	#[cfg(feature = "clock")]
	use crate::offset::{Local, TimeZone};

	#[test]
	#[cfg(feature = "clock")]
	fn test_years_elapsed() {
	const WEEKS_PER_YEAR: f32 = 52.1775;

	// This is always at least one year because 1 year = 52.1775 weeks.
	let one_year_ago = Utc::today() - TimeDelta::weeks((WEEKS_PER_YEAR * 1.5).ceil() as i64);
	// A bit more than 2 years.
	let two_year_ago = Utc::today() - TimeDelta::weeks((WEEKS_PER_YEAR * 2.5).ceil() as i64);

	assert_eq!(Utc::today().years_since(one_year_ago), Some(1));
	assert_eq!(Utc::today().years_since(two_year_ago), Some(2));

	// If the given DateTime is later than now, the function will always return 0.
	let future = Utc::today() + TimeDelta::weeks(12);
	assert_eq!(Utc::today().years_since(future), None);
	}

	#[test]
	fn test_date_add_assign() {
	let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();
	let date = Date::<Utc>::from_utc(naivedate, Utc);
	let mut date_add = date;

	date_add += TimeDelta::days(5);
	assert_eq!(date_add, date + TimeDelta::days(5));

	let timezone = FixedOffset::east_opt(60 * 60).unwrap();
	let date = date.with_timezone(&timezone);
	let date_add = date_add.with_timezone(&timezone);

	assert_eq!(date_add, date + TimeDelta::days(5));

	let timezone = FixedOffset::west_opt(2 * 60 * 60).unwrap();
	let date = date.with_timezone(&timezone);
	let date_add = date_add.with_timezone(&timezone);

	assert_eq!(date_add, date + TimeDelta::days(5));
	}

	#[test]
	#[cfg(feature = "clock")]
	fn test_date_add_assign_local() {
	let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();

	let date = Local.from_utc_date(&naivedate);
	let mut date_add = date;

	date_add += TimeDelta::days(5);
	assert_eq!(date_add, date + TimeDelta::days(5));
	}

	#[test]
	fn test_date_sub_assign() {
	let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();
	let date = Date::<Utc>::from_utc(naivedate, Utc);
	let mut date_sub = date;

	date_sub -= TimeDelta::days(5);
	assert_eq!(date_sub, date - TimeDelta::days(5));

	let timezone = FixedOffset::east_opt(60 * 60).unwrap();
	let date = date.with_timezone(&timezone);
	let date_sub = date_sub.with_timezone(&timezone);

	assert_eq!(date_sub, date - TimeDelta::days(5));

	let timezone = FixedOffset::west_opt(2 * 60 * 60).unwrap();
	let date = date.with_timezone(&timezone);
	let date_sub = date_sub.with_timezone(&timezone);

	assert_eq!(date_sub, date - TimeDelta::days(5));
	}

	#[test]
	#[cfg(feature = "clock")]
	fn test_date_sub_assign_local() {
	let naivedate = NaiveDate::from_ymd_opt(2000, 1, 1).unwrap();

	let date = Local.from_utc_date(&naivedate);
	let mut date_sub = date;

	date_sub -= TimeDelta::days(5);
	assert_eq!(date_sub, date - TimeDelta::days(5));
	}
	}