use bstr::BString; use crate::{time::Sign, Time}; /// Serialization with standard `git` formatimpl Time {    /// Serialize this instance into memory, similar to what [`write_to()`][Self::write_to()] would do with arbitrary `Write` implementations.    pub fn to_bstring(&self) -> BString {        let mut buf = Vec::with_capacity(64);        self.write_to(&mut buf).expect("write to memory cannot fail");        buf.into()    }     /// Serialize this instance to `out` in a format suitable for use in header fields of serialized git commits or tags.    pub fn write_to(&self, out: &mut dyn std::io::Write) -> std::io::Result<()> {        let mut itoa = itoa::Buffer::new();        out.write_all(itoa.format(self.seconds).as_bytes())?;        out.write_all(b" ")?;        out.write_all(match self.sign {            Sign::Plus => b"+",            Sign::Minus => b"-",        })?;         const ZERO: &[u8; 1] = b"0";         const SECONDS_PER_HOUR: u32 = 60 * 60;        let offset = self.offset.unsigned_abs();        let hours = offset / SECONDS_PER_HOUR;        assert!(hours < 25, "offset is more than a day: {hours}");        let minutes = (offset - (hours * SECONDS_PER_HOUR)) / 60;         if hours < 10 {            out.write_all(ZERO)?;        }        out.write_all(itoa.format(hours).as_bytes())?;         if minutes < 10 {            out.write_all(ZERO)?;        }        out.write_all(itoa.format(minutes).as_bytes()).map(|_| ())    }     /// Computes the number of bytes necessary to write it using [`Time::write_to()`].    pub fn size(&self) -> usize {        (if self.seconds >= 1_000_000_000_000_000_000 {            19        } else if self.seconds >= 100_000_000_000_000_000 {            18        } else if self.seconds >= 10_000_000_000_000_000 {            17        } else if self.seconds >= 1_000_000_000_000_000 {            16        } else if self.seconds >= 100_000_000_000_000 {            15        } else if self.seconds >= 10_000_000_000_000 {            14        } else if self.seconds >= 1_000_000_000_000 {            13        } else if self.seconds >= 100_000_000_000 {            12        } else if self.seconds >= 10_000_000_000 {            11        } else if self.seconds >= 1_000_000_000 {            10        } else if self.seconds >= 100_000_000 {            9        } else if self.seconds >= 10_000_000 {            8        } else if self.seconds >= 1_000_000 {            7        } else if self.seconds >= 100_000 {            6        } else if self.seconds >= 10_000 {            5        } else if self.seconds >= 1_000 {            4        } else if self.seconds >= 100 {            3        } else if self.seconds >= 10 {            2        } else if self.seconds >= 0 {            1            // from here, it's sign + num-digits characters        } else if self.seconds >= -10 {            2        } else if self.seconds >= -100 {            3        } else if self.seconds >= -1_000 {            4        } else if self.seconds >= -10_000 {            5        } else if self.seconds >= -100_000 {            6        } else if self.seconds >= -1_000_000 {            7        } else if self.seconds >= -10_000_000 {            8        } else if self.seconds >= -100_000_000 {            9        } else if self.seconds >= -1_000_000_000 {            10        } else if self.seconds >= -10_000_000_000 {            11        } else if self.seconds >= -100_000_000_000 {            12        } else if self.seconds >= -1_000_000_000_000 {            13        } else if self.seconds >= -10_000_000_000_000 {            14        } else if self.seconds >= -100_000_000_000_000 {            15        } else if self.seconds >= -1_000_000_000_000_000 {            16        } else if self.seconds >= -10_000_000_000_000_000 {            17        } else if self.seconds >= -100_000_000_000_000_000 {            18        } else if self.seconds >= -1_000_000_000_000_000_000 {            19        } else {            20        }) + 2 /*space + offset sign*/ + 2 /*offset hours*/ + 2 /*offset minutes*/    }}