use std::io; use crate::{Sign, Time, SPACE}; impl From<i32> for Sign {    fn from(v: i32) -> Self {        if v < 0 {            Sign::Minus        } else {            Sign::Plus        }    }} impl Time {    /// 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, mut out: impl io::Write) -> io::Result<()> {        itoa::write(&mut out, self.time)?;        out.write_all(SPACE)?;        out.write_all(match self.sign {            Sign::Plus => b"+",            Sign::Minus => b"-",        })?;         const ZERO: &[u8; 1] = b"0";         const SECONDS_PER_HOUR: i32 = 60 * 60;        let offset = self.offset.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)?;        }        itoa::write(&mut out, hours)?;         if minutes < 10 {            out.write_all(ZERO)?;        }        itoa::write(&mut out, minutes).map(|_| ())    }    /// Computes the number of bytes necessary to render this time    pub fn size(&self) -> usize {        // TODO: this is not year 2038 safe…but we also can't parse larger numbers (or represent them) anyway. It's a trap nonetheless        //       that can be fixed by increasing the size to usize.        (if self.time >= 1_000_000_000 {            10        } else if self.time >= 100_000_000 {            9        } else if self.time >= 10_000_000 {            8        } else if self.time >= 1_000_000 {            7        } else if self.time >= 100_000 {            6        } else if self.time >= 10_000 {            5        } else if self.time >= 1_000 {            4        } else if self.time >= 100 {            3        } else if self.time >= 10 {            2        } else {            1        }) + 2 /*space + sign*/ + 2 /*hours*/ + 2 /*minutes*/    }}