Make eligible functions const.

src/format/locales.rs

@@ -1,33 +1,33 @@
 use pure_rust_locales::{locale_match, Locale};
 
-pub(crate) fn short_months(locale: Locale) -> &'static [&'static str] {
+pub(crate) const fn short_months(locale: Locale) -> &'static [&'static str] {
     locale_match!(locale => LC_TIME::ABMON)
 }
 
-pub(crate) fn long_months(locale: Locale) -> &'static [&'static str] {
+pub(crate) const fn long_months(locale: Locale) -> &'static [&'static str] {
     locale_match!(locale => LC_TIME::MON)
 }
 
-pub(crate) fn short_weekdays(locale: Locale) -> &'static [&'static str] {
+pub(crate) const fn short_weekdays(locale: Locale) -> &'static [&'static str] {
     locale_match!(locale => LC_TIME::ABDAY)
 }
 
-pub(crate) fn long_weekdays(locale: Locale) -> &'static [&'static str] {
+pub(crate) const fn long_weekdays(locale: Locale) -> &'static [&'static str] {
     locale_match!(locale => LC_TIME::DAY)
 }
 
-pub(crate) fn am_pm(locale: Locale) -> &'static [&'static str] {
+pub(crate) const fn am_pm(locale: Locale) -> &'static [&'static str] {
     locale_match!(locale => LC_TIME::AM_PM)
 }
 
-pub(crate) fn d_fmt(locale: Locale) -> &'static str {
+pub(crate) const fn d_fmt(locale: Locale) -> &'static str {
     locale_match!(locale => LC_TIME::D_FMT)
 }
 
-pub(crate) fn d_t_fmt(locale: Locale) -> &'static str {
+pub(crate) const fn d_t_fmt(locale: Locale) -> &'static str {
     locale_match!(locale => LC_TIME::D_T_FMT)
 }
 
-pub(crate) fn t_fmt(locale: Locale) -> &'static str {
+pub(crate) const fn t_fmt(locale: Locale) -> &'static str {
     locale_match!(locale => LC_TIME::T_FMT)
 }

src/format/mod.rs

@@ -350,7 +350,7 @@ pub struct ParseError(ParseErrorKind);
 
 impl ParseError {
     /// The category of parse error
-    pub fn kind(&self) -> ParseErrorKind {
+    pub const fn kind(&self) -> ParseErrorKind {
         self.0
     }
 }

src/format/scan.rs

@@ -222,7 +222,7 @@ fn timezone_offset_internal<F>(
 where
     F: FnMut(&str) -> ParseResult<&str>,
 {
-    fn digits(s: &str) -> ParseResult<(u8, u8)> {
+    const fn digits(s: &str) -> ParseResult<(u8, u8)> {
         let b = s.as_bytes();
         if b.len() < 2 {
             Err(TOO_SHORT)

src/lib.rs

@@ -498,7 +498,7 @@ pub struct OutOfRange {
 }
 
 impl OutOfRange {
-    fn new() -> OutOfRange {
+    const fn new() -> OutOfRange {
         OutOfRange { _private: () }
     }
 }

src/month.rs

@@ -66,7 +66,7 @@ impl Month {
     /// ----------- | ---------  | ---------- | --- | ---------
     /// `m.succ()`: | `February` | `March`    | `...` | `January`
     #[inline]
-    pub fn succ(&self) -> Month {
+    pub const fn succ(&self) -> Month {
         match *self {
             Month::January => Month::February,
             Month::February => Month::March,
@@ -89,7 +89,7 @@ impl Month {
     /// ----------- | ---------  | ---------- | --- | ---------
     /// `m.pred()`: | `December` | `January`  | `...` | `November`
     #[inline]
-    pub fn pred(&self) -> Month {
+    pub const fn pred(&self) -> Month {
         match *self {
             Month::January => Month::December,
             Month::February => Month::January,
@@ -112,7 +112,7 @@ impl Month {
     /// -------------------------| --------- | ---------- | --- | -----
     /// `m.number_from_month()`: | 1         | 2          | `...` | 12
     #[inline]
-    pub fn number_from_month(&self) -> u32 {
+    pub const fn number_from_month(&self) -> u32 {
         match *self {
             Month::January => 1,
             Month::February => 2,
@@ -136,7 +136,7 @@ impl Month {
     ///
     /// assert_eq!(Month::January.name(), "January")
     /// ```
-    pub fn name(&self) -> &'static str {
+    pub const fn name(&self) -> &'static str {
         match *self {
             Month::January => "January",
             Month::February => "February",
@@ -183,7 +183,7 @@ pub struct Months(pub(crate) u32);
 
 impl Months {
     /// Construct a new `Months` from a number of months
-    pub fn new(num: u32) -> Self {
+    pub const fn new(num: u32) -> Self {
         Self(num)
     }
 }

src/naive/date.rs

@@ -129,7 +129,7 @@ pub struct Days(pub(crate) u64);
 
 impl Days {
     /// Construct a new `Days` from a number of days
-    pub fn new(num: u64) -> Self {
+    pub const fn new(num: u64) -> Self {
         Self(num)
     }
 }
@@ -691,7 +691,7 @@ impl NaiveDate {
     /// assert_eq!(dt.time(), t);
     /// ```
     #[inline]
-    pub fn and_time(&self, time: NaiveTime) -> NaiveDateTime {
+    pub const fn and_time(&self, time: NaiveTime) -> NaiveDateTime {
         NaiveDateTime::new(*self, time)
     }
 
@@ -881,7 +881,7 @@ impl NaiveDate {
 
     /// Returns the packed ordinal-flags.
     #[inline]
-    fn of(&self) -> Of {
+    const fn of(&self) -> Of {
         Of((self.ymdf & 0b1_1111_1111_1111) as u32)
     }
 
@@ -1204,7 +1204,7 @@ impl NaiveDate {
     /// }
     /// ```
     #[inline]
-    pub fn iter_days(&self) -> NaiveDateDaysIterator {
+    pub const fn iter_days(&self) -> NaiveDateDaysIterator {
         NaiveDateDaysIterator { value: *self }
     }
 
@@ -1235,14 +1235,14 @@ impl NaiveDate {
     /// }
     /// ```
     #[inline]
-    pub fn iter_weeks(&self) -> NaiveDateWeeksIterator {
+    pub const fn iter_weeks(&self) -> NaiveDateWeeksIterator {
         NaiveDateWeeksIterator { value: *self }
     }
 
     /// Returns the [`NaiveWeek`] that the date belongs to, starting with the [`Weekday`]
     /// specified.
     #[inline]
-    pub fn week(&self, start: Weekday) -> NaiveWeek {
+    pub const fn week(&self, start: Weekday) -> NaiveWeek {
         NaiveWeek { date: *self, start }
     }
 

src/naive/datetime/mod.rs

@@ -126,7 +126,7 @@ impl NaiveDateTime {
     /// assert_eq!(dt.time(), t);
     /// ```
     #[inline]
-    pub fn new(date: NaiveDate, time: NaiveTime) -> NaiveDateTime {
+    pub const fn new(date: NaiveDate, time: NaiveTime) -> NaiveDateTime {
         NaiveDateTime { date, time }
     }
 
@@ -320,7 +320,7 @@ impl NaiveDateTime {
     /// assert_eq!(dt.date(), NaiveDate::from_ymd_opt(2016, 7, 8).unwrap());
     /// ```
     #[inline]
-    pub fn date(&self) -> NaiveDate {
+    pub const fn date(&self) -> NaiveDate {
         self.date
     }
 
@@ -335,7 +335,7 @@ impl NaiveDateTime {
     /// assert_eq!(dt.time(), NaiveTime::from_hms_opt(9, 10, 11).unwrap());
     /// ```
     #[inline]
-    pub fn time(&self) -> NaiveTime {
+    pub const fn time(&self) -> NaiveTime {
         self.time
     }
 

src/naive/internals.rs

@@ -143,7 +143,7 @@ impl YearFlags {
     }
 
     #[inline]
-    pub(super) fn nisoweeks(&self) -> u32 {
+    pub(super) const fn nisoweeks(&self) -> u32 {
         let YearFlags(flags) = *self;
         52 + ((0b0000_0100_0000_0110 >> flags as usize) & 1)
     }
@@ -296,13 +296,13 @@ impl Of {
     }
 
     #[inline]
-    pub(super) fn ordinal(&self) -> u32 {
+    pub(super) const fn ordinal(&self) -> u32 {
         let Of(of) = *self;
         of >> 4
     }
 
     #[inline]
-    pub(super) fn with_ordinal(&self, ordinal: u32) -> Option<Of> {
+    pub(super) const fn with_ordinal(&self, ordinal: u32) -> Option<Of> {
         if ordinal > 366 {
             return None;
         }
@@ -312,7 +312,7 @@ impl Of {
     }
 
     #[inline]
-    pub(super) fn flags(&self) -> YearFlags {
+    pub(super) const fn flags(&self) -> YearFlags {
         let Of(of) = *self;
         YearFlags((of & 0b1111) as u8)
     }
@@ -338,13 +338,13 @@ impl Of {
     }
 
     #[inline]
-    pub(super) fn succ(&self) -> Of {
+    pub(super) const fn succ(&self) -> Of {
         let Of(of) = *self;
         Of(of + (1 << 4))
     }
 
     #[inline]
-    pub(super) fn pred(&self) -> Of {
+    pub(super) const fn pred(&self) -> Of {
         let Of(of) = *self;
         Of(of - (1 << 4))
     }
@@ -400,13 +400,13 @@ impl Mdf {
     }
 
     #[inline]
-    pub(super) fn month(&self) -> u32 {
+    pub(super) const fn month(&self) -> u32 {
         let Mdf(mdf) = *self;
         mdf >> 9
     }
 
     #[inline]
-    pub(super) fn with_month(&self, month: u32) -> Option<Mdf> {
+    pub(super) const fn with_month(&self, month: u32) -> Option<Mdf> {
         if month > 12 {
             return None;
         }
@@ -416,13 +416,13 @@ impl Mdf {
     }
 
     #[inline]
-    pub(super) fn day(&self) -> u32 {
+    pub(super) const fn day(&self) -> u32 {
         let Mdf(mdf) = *self;
         (mdf >> 4) & 0b1_1111
     }
 
     #[inline]
-    pub(super) fn with_day(&self, day: u32) -> Option<Mdf> {
+    pub(super) const fn with_day(&self, day: u32) -> Option<Mdf> {
         if day > 31 {
             return None;
         }

src/naive/isoweek.rs

@@ -71,7 +71,7 @@ impl IsoWeek {
     /// assert_eq!(d, NaiveDate::from_ymd_opt(2014, 12, 29).unwrap());
     /// ```
     #[inline]
-    pub fn year(&self) -> i32 {
+    pub const fn year(&self) -> i32 {
         self.ywf >> 10
     }
 
@@ -88,7 +88,7 @@ impl IsoWeek {
     /// assert_eq!(d.iso_week().week(), 15);
     /// ```
     #[inline]
-    pub fn week(&self) -> u32 {
+    pub const fn week(&self) -> u32 {
         ((self.ywf >> 4) & 0x3f) as u32
     }
 
@@ -105,7 +105,7 @@ impl IsoWeek {
     /// assert_eq!(d.iso_week().week0(), 14);
     /// ```
     #[inline]
-    pub fn week0(&self) -> u32 {
+    pub const fn week0(&self) -> u32 {
         ((self.ywf >> 4) & 0x3f) as u32 - 1
     }
 }

src/naive/time/mod.rs

@@ -235,7 +235,7 @@ impl NaiveTime {
     /// assert!(from_hms_opt(23, 59, 60).is_none());
     /// ```
     #[inline]
-    pub fn from_hms_opt(hour: u32, min: u32, sec: u32) -> Option<NaiveTime> {
+    pub const fn from_hms_opt(hour: u32, min: u32, sec: u32) -> Option<NaiveTime> {
         NaiveTime::from_hms_nano_opt(hour, min, sec, 0)
     }
 
@@ -354,7 +354,7 @@ impl NaiveTime {
     /// assert!(from_hmsn_opt(23, 59, 59, 2_000_000_000).is_none());
     /// ```
     #[inline]
-    pub fn from_hms_nano_opt(hour: u32, min: u32, sec: u32, nano: u32) -> Option<NaiveTime> {
+    pub const fn from_hms_nano_opt(hour: u32, min: u32, sec: u32, nano: u32) -> Option<NaiveTime> {
         if hour >= 24 || min >= 60 || sec >= 60 || nano >= 2_000_000_000 {
             return None;
         }
@@ -395,7 +395,7 @@ impl NaiveTime {
     /// assert!(from_nsecs_opt(86399, 2_000_000_000).is_none());
     /// ```
     #[inline]
-    pub fn from_num_seconds_from_midnight_opt(secs: u32, nano: u32) -> Option<NaiveTime> {
+    pub const fn from_num_seconds_from_midnight_opt(secs: u32, nano: u32) -> Option<NaiveTime> {
         if secs >= 86_400 || nano >= 2_000_000_000 {
             return None;
         }

src/offset/fixed.rs

@@ -52,7 +52,7 @@ impl FixedOffset {
     ///                                           .and_hms_opt(0, 0, 0).unwrap();
     /// assert_eq!(&datetime.to_rfc3339(), "2016-11-08T00:00:00+05:00")
     /// ```
-    pub fn east_opt(secs: i32) -> Option<FixedOffset> {
+    pub const fn east_opt(secs: i32) -> Option<FixedOffset> {
         if -86_400 < secs && secs < 86_400 {
             Some(FixedOffset { local_minus_utc: secs })
         } else {
@@ -83,7 +83,7 @@ impl FixedOffset {
     ///                                           .and_hms_opt(0, 0, 0).unwrap();
     /// assert_eq!(&datetime.to_rfc3339(), "2016-11-08T00:00:00-05:00")
     /// ```
-    pub fn west_opt(secs: i32) -> Option<FixedOffset> {
+    pub const fn west_opt(secs: i32) -> Option<FixedOffset> {
         if -86_400 < secs && secs < 86_400 {
             Some(FixedOffset { local_minus_utc: -secs })
         } else {
@@ -93,13 +93,13 @@ impl FixedOffset {
 
     /// Returns the number of seconds to add to convert from UTC to the local time.
     #[inline]
-    pub fn local_minus_utc(&self) -> i32 {
+    pub const fn local_minus_utc(&self) -> i32 {
         self.local_minus_utc
     }
 
     /// Returns the number of seconds to add to convert from the local time to UTC.
     #[inline]
-    pub fn utc_minus_local(&self) -> i32 {
+    pub const fn utc_minus_local(&self) -> i32 {
         -self.local_minus_utc
     }
 }

src/offset/local/tz_info/mod.rs

@@ -102,7 +102,7 @@ impl From<Utf8Error> for Error {
 
 // MSRV: 1.38
 #[inline]
-fn rem_euclid(v: i64, rhs: i64) -> i64 {
+const fn rem_euclid(v: i64, rhs: i64) -> i64 {
     let r = v % rhs;
     if r < 0 {
         if rhs < 0 {

src/offset/local/tz_info/parser.rs

@@ -224,7 +224,7 @@ pub(crate) struct Cursor<'a> {
 
 impl<'a> Cursor<'a> {
     /// Construct a new `Cursor` from remaining data
-    pub(crate) fn new(remaining: &'a [u8]) -> Self {
+    pub(crate) const fn new(remaining: &'a [u8]) -> Self {
         Self { remaining, read_count: 0 }
     }
 
@@ -233,12 +233,12 @@ impl<'a> Cursor<'a> {
     }
 
     /// Returns remaining data
-    pub(crate) fn remaining(&self) -> &'a [u8] {
+    pub(crate) const fn remaining(&self) -> &'a [u8] {
         self.remaining
     }
 
     /// Returns `true` if data is remaining
-    pub(crate) fn is_empty(&self) -> bool {
+    pub(crate) const fn is_empty(&self) -> bool {
         self.remaining.is_empty()
     }