/rust/registry/src/index.crates.io-1949cf8c6b5b557f/time-0.3.47/src/month.rs

Source
//! The `Month` enum and its associated `impl`s.

use core::fmt;
use core::num::NonZero;
use core::str::FromStr;

use powerfmt::smart_display::{FormatterOptions, Metadata, SmartDisplay};

use self::Month::*;
use crate::{error, util};

/// Months of the year.
#[repr(u8)]
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum Month {
    #[expect(missing_docs)]
    January = 1,
    #[expect(missing_docs)]
    February = 2,
    #[expect(missing_docs)]
    March = 3,
    #[expect(missing_docs)]
    April = 4,
    #[expect(missing_docs)]
    May = 5,
    #[expect(missing_docs)]
    June = 6,
    #[expect(missing_docs)]
    July = 7,
    #[expect(missing_docs)]
    August = 8,
    #[expect(missing_docs)]
    September = 9,
    #[expect(missing_docs)]
    October = 10,
    #[expect(missing_docs)]
    November = 11,
    #[expect(missing_docs)]
    December = 12,
}

impl Month {
    /// Create a `Month` from its numerical value.
    #[inline]
    pub(crate) const fn from_number(n: NonZero<u8>) -> Result<Self, error::ComponentRange> {
        match n.get() {
            1 => Ok(January),
            2 => Ok(February),
            3 => Ok(March),
            4 => Ok(April),
            5 => Ok(May),
            6 => Ok(June),
            7 => Ok(July),
            8 => Ok(August),
            9 => Ok(September),
            10 => Ok(October),
            11 => Ok(November),
            12 => Ok(December),
            _ => Err(error::ComponentRange::unconditional("month")),
        }
    }

    /// Get the number of days in the month of a given year.
    ///
    /// ```rust
    /// # use time::Month;
    /// assert_eq!(Month::February.length(2020), 29);
    /// ```
    #[inline]
    pub const fn length(self, year: i32) -> u8 {
        util::days_in_month(self, year)
    }

    /// Get the previous month.
    ///
    /// ```rust
    /// # use time::Month;
    /// assert_eq!(Month::January.previous(), Month::December);
    /// ```
    #[inline]
    pub const fn previous(self) -> Self {
        match self {
            January => December,
            February => January,
            March => February,
            April => March,
            May => April,
            June => May,
            July => June,
            August => July,
            September => August,
            October => September,
            November => October,
            December => November,
        }
    }

    /// Get the next month.
    ///
    /// ```rust
    /// # use time::Month;
    /// assert_eq!(Month::January.next(), Month::February);
    /// ```
    #[inline]
    pub const fn next(self) -> Self {
        match self {
            January => February,
            February => March,
            March => April,
            April => May,
            May => June,
            June => July,
            July => August,
            August => September,
            September => October,
            October => November,
            November => December,
            December => January,
        }
    }

    /// Get n-th next month.
    ///
    /// ```rust
    /// # use time::Month;
    /// assert_eq!(Month::January.nth_next(4), Month::May);
    /// assert_eq!(Month::July.nth_next(9), Month::April);
    /// ```
    #[inline]
    pub const fn nth_next(self, n: u8) -> Self {
        match (self as u8 - 1 + n % 12) % 12 {
            0 => January,
            1 => February,
            2 => March,
            3 => April,
            4 => May,
            5 => June,
            6 => July,
            7 => August,
            8 => September,
            9 => October,
            10 => November,
            val => {
                debug_assert!(val == 11);
                December
            }
        }
    }

    /// Get n-th previous month.
    ///
    /// ```rust
    /// # use time::Month;
    /// assert_eq!(Month::January.nth_prev(4), Month::September);
    /// assert_eq!(Month::July.nth_prev(9), Month::October);
    /// ```
    #[inline]
    pub const fn nth_prev(self, n: u8) -> Self {
        match self as i8 - 1 - (n % 12).cast_signed() {
            1 | -11 => February,
            2 | -10 => March,
            3 | -9 => April,
            4 | -8 => May,
            5 | -7 => June,
            6 | -6 => July,
            7 | -5 => August,
            8 | -4 => September,
            9 | -3 => October,
            10 | -2 => November,
            11 | -1 => December,
            val => {
                debug_assert!(val == 0);
                January
            }
        }
    }
}

mod private {
    /// Metadata for `Month`.
    #[non_exhaustive]
    #[derive(Debug, Clone, Copy)]
    pub struct MonthMetadata;
}
use private::MonthMetadata;

impl SmartDisplay for Month {
    type Metadata = MonthMetadata;

    #[inline]
    fn metadata(&self, _: FormatterOptions) -> Metadata<'_, Self> {
        match self {
            January => Metadata::new(7, self, MonthMetadata),
            February => Metadata::new(8, self, MonthMetadata),
            March => Metadata::new(5, self, MonthMetadata),
            April => Metadata::new(5, self, MonthMetadata),
            May => Metadata::new(3, self, MonthMetadata),
            June => Metadata::new(4, self, MonthMetadata),
            July => Metadata::new(4, self, MonthMetadata),
            August => Metadata::new(6, self, MonthMetadata),
            September => Metadata::new(9, self, MonthMetadata),
            October => Metadata::new(7, self, MonthMetadata),
            November => Metadata::new(8, self, MonthMetadata),
            December => Metadata::new(8, self, MonthMetadata),
        }
    }

    #[inline]
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.pad(match self {
            January => "January",
            February => "February",
            March => "March",
            April => "April",
            May => "May",
            June => "June",
            July => "July",
            August => "August",
            September => "September",
            October => "October",
            November => "November",
            December => "December",
        })
    }
}

impl fmt::Display for Month {
    #[inline]
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        SmartDisplay::fmt(self, f)
    }
}

impl FromStr for Month {
    type Err = error::InvalidVariant;

    #[inline]
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s {
            "January" => Ok(January),
            "February" => Ok(February),
            "March" => Ok(March),
            "April" => Ok(April),
            "May" => Ok(May),
            "June" => Ok(June),
            "July" => Ok(July),
            "August" => Ok(August),
            "September" => Ok(September),
            "October" => Ok(October),
            "November" => Ok(November),
            "December" => Ok(December),
            _ => Err(error::InvalidVariant),
        }
    }
}

impl From<Month> for u8 {
    #[inline]
    fn from(month: Month) -> Self {
        month as Self
    }
}

impl TryFrom<u8> for Month {
    type Error = error::ComponentRange;

    #[inline]
    fn try_from(value: u8) -> Result<Self, Self::Error> {
        match NonZero::new(value) {
            Some(value) => Self::from_number(value),
            None => Err(error::ComponentRange::unconditional("month")),
        }
    }
}

Coverage Report

Created: 2026-03-19 06:32

Line	Count	Source
1		//! The `Month` enum and its associated `impl`s.
2
3		use core::fmt;
4		use core::num::NonZero;
5		use core::str::FromStr;
6
7		use powerfmt::smart_display::{FormatterOptions, Metadata, SmartDisplay};
8
9		use self::Month::*;
10		use crate::{error, util};
11
12		/// Months of the year.
13		#[repr(u8)]
14		#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
15		pub enum Month {
16		#[expect(missing_docs)]
17		January = 1,
18		#[expect(missing_docs)]
19		February = 2,
20		#[expect(missing_docs)]
21		March = 3,
22		#[expect(missing_docs)]
23		April = 4,
24		#[expect(missing_docs)]
25		May = 5,
26		#[expect(missing_docs)]
27		June = 6,
28		#[expect(missing_docs)]
29		July = 7,
30		#[expect(missing_docs)]
31		August = 8,
32		#[expect(missing_docs)]
33		September = 9,
34		#[expect(missing_docs)]
35		October = 10,
36		#[expect(missing_docs)]
37		November = 11,
38		#[expect(missing_docs)]
39		December = 12,
40		}
41
42		impl Month {
43		/// Create a `Month` from its numerical value.
44		#[inline]
45	0	pub(crate) const fn from_number(n: NonZero<u8>) -> Result<Self, error::ComponentRange> {
46	0	match n.get() {
47	0	1 => Ok(January),
48	0	2 => Ok(February),
49	0	3 => Ok(March),
50	0	4 => Ok(April),
51	0	5 => Ok(May),
52	0	6 => Ok(June),
53	0	7 => Ok(July),
54	0	8 => Ok(August),
55	0	9 => Ok(September),
56	0	10 => Ok(October),
57	0	11 => Ok(November),
58	0	12 => Ok(December),
59	0	_ => Err(error::ComponentRange::unconditional("month")),
60		}
61	0	} Unexecuted instantiation: <time::month::Month>::from_number Unexecuted instantiation: <time::month::Month>::from_number
62
63		/// Get the number of days in the month of a given year.
64		///
65		/// ```rust
66		/// # use time::Month;
67		/// assert_eq!(Month::February.length(2020), 29);
68		/// ```
69		#[inline]
70	0	pub const fn length(self, year: i32) -> u8 {
71	0	util::days_in_month(self, year)
72	0	}
73
74		/// Get the previous month.
75		///
76		/// ```rust
77		/// # use time::Month;
78		/// assert_eq!(Month::January.previous(), Month::December);
79		/// ```
80		#[inline]
81	0	pub const fn previous(self) -> Self {
82	0	match self {
83	0	January => December,
84	0	February => January,
85	0	March => February,
86	0	April => March,
87	0	May => April,
88	0	June => May,
89	0	July => June,
90	0	August => July,
91	0	September => August,
92	0	October => September,
93	0	November => October,
94	0	December => November,
95		}
96	0	}
97
98		/// Get the next month.
99		///
100		/// ```rust
101		/// # use time::Month;
102		/// assert_eq!(Month::January.next(), Month::February);
103		/// ```
104		#[inline]
105	0	pub const fn next(self) -> Self {
106	0	match self {
107	0	January => February,
108	0	February => March,
109	0	March => April,
110	0	April => May,
111	0	May => June,
112	0	June => July,
113	0	July => August,
114	0	August => September,
115	0	September => October,
116	0	October => November,
117	0	November => December,
118	0	December => January,
119		}
120	0	}
121
122		/// Get n-th next month.
123		///
124		/// ```rust
125		/// # use time::Month;
126		/// assert_eq!(Month::January.nth_next(4), Month::May);
127		/// assert_eq!(Month::July.nth_next(9), Month::April);
128		/// ```
129		#[inline]
130	0	pub const fn nth_next(self, n: u8) -> Self {
131	0	match (self as u8 - 1 + n % 12) % 12 {
132	0	0 => January,
133	0	1 => February,
134	0	2 => March,
135	0	3 => April,
136	0	4 => May,
137	0	5 => June,
138	0	6 => July,
139	0	7 => August,
140	0	8 => September,
141	0	9 => October,
142	0	10 => November,
143	0	val => {
144	0	debug_assert!(val == 11);
145	0	December
146		}
147		}
148	0	}
149
150		/// Get n-th previous month.
151		///
152		/// ```rust
153		/// # use time::Month;
154		/// assert_eq!(Month::January.nth_prev(4), Month::September);
155		/// assert_eq!(Month::July.nth_prev(9), Month::October);
156		/// ```
157		#[inline]
158	0	pub const fn nth_prev(self, n: u8) -> Self {
159	0	match self as i8 - 1 - (n % 12).cast_signed() {
160	0	1 \| -11 => February,
161	0	2 \| -10 => March,
162	0	3 \| -9 => April,
163	0	4 \| -8 => May,
164	0	5 \| -7 => June,
165	0	6 \| -6 => July,
166	0	7 \| -5 => August,
167	0	8 \| -4 => September,
168	0	9 \| -3 => October,
169	0	10 \| -2 => November,
170	0	11 \| -1 => December,
171	0	val => {
172	0	debug_assert!(val == 0);
173	0	January
174		}
175		}
176	0	}
177		}
178
179		mod private {
180		/// Metadata for `Month`.
181		#[non_exhaustive]
182		#[derive(Debug, Clone, Copy)]
183		pub struct MonthMetadata;
184		}
185		use private::MonthMetadata;
186
187		impl SmartDisplay for Month {
188		type Metadata = MonthMetadata;
189
190		#[inline]
191	0	fn metadata(&self, _: FormatterOptions) -> Metadata<'_, Self> {
192	0	match self {
193	0	January => Metadata::new(7, self, MonthMetadata),
194	0	February => Metadata::new(8, self, MonthMetadata),
195	0	March => Metadata::new(5, self, MonthMetadata),
196	0	April => Metadata::new(5, self, MonthMetadata),
197	0	May => Metadata::new(3, self, MonthMetadata),
198	0	June => Metadata::new(4, self, MonthMetadata),
199	0	July => Metadata::new(4, self, MonthMetadata),
200	0	August => Metadata::new(6, self, MonthMetadata),
201	0	September => Metadata::new(9, self, MonthMetadata),
202	0	October => Metadata::new(7, self, MonthMetadata),
203	0	November => Metadata::new(8, self, MonthMetadata),
204	0	December => Metadata::new(8, self, MonthMetadata),
205		}
206	0	}
207
208		#[inline]
209	0	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
210	0	f.pad(match self {
211	0	January => "January",
212	0	February => "February",
213	0	March => "March",
214	0	April => "April",
215	0	May => "May",
216	0	June => "June",
217	0	July => "July",
218	0	August => "August",
219	0	September => "September",
220	0	October => "October",
221	0	November => "November",
222	0	December => "December",
223		})
224	0	}
225		}
226
227		impl fmt::Display for Month {
228		#[inline]
229	0	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
230	0	SmartDisplay::fmt(self, f)
231	0	}
232		}
233
234		impl FromStr for Month {
235		type Err = error::InvalidVariant;
236
237		#[inline]
238	0	fn from_str(s: &str) -> Result<Self, Self::Err> {
239	0	match s {
240	0	"January" => Ok(January),
241	0	"February" => Ok(February),
242	0	"March" => Ok(March),
243	0	"April" => Ok(April),
244	0	"May" => Ok(May),
245	0	"June" => Ok(June),
246	0	"July" => Ok(July),
247	0	"August" => Ok(August),
248	0	"September" => Ok(September),
249	0	"October" => Ok(October),
250	0	"November" => Ok(November),
251	0	"December" => Ok(December),
252	0	_ => Err(error::InvalidVariant),
253		}
254	0	}
255		}
256
257		impl From<Month> for u8 {
258		#[inline]
259	0	fn from(month: Month) -> Self {
260	0	month as Self
261	0	} Unexecuted instantiation: <u8 as core::convert::From<time::month::Month>>::from Unexecuted instantiation: <u8 as core::convert::From<time::month::Month>>::from
262		}
263
264		impl TryFrom<u8> for Month {
265		type Error = error::ComponentRange;
266
267		#[inline]
268	0	fn try_from(value: u8) -> Result<Self, Self::Error> {
269	0	match NonZero::new(value) {
270	0	Some(value) => Self::from_number(value),
271	0	None => Err(error::ComponentRange::unconditional("month")),
272		}
273	0	}
274		}