Trait chrono::SubsecRound
source · [−]pub trait SubsecRound {
fn round_subsecs(self, digits: u16) -> Self;
fn trunc_subsecs(self, digits: u16) -> Self;
}Expand description
Extension trait for subsecond rounding or truncation to a maximum number of digits. Rounding can be used to decrease the error variance when serializing/persisting to lower precision. Truncation is the default behavior in Chrono display formatting. Either can be used to guarantee equality (e.g. for testing) when round-tripping through a lower precision format.
Required methods
fn round_subsecs(self, digits: u16) -> Self
fn round_subsecs(self, digits: u16) -> Self
Return a copy rounded to the specified number of subsecond digits. With 9 or more digits, self is returned unmodified. Halfway values are rounded up (away from zero).
Example
let dt = Utc.ymd(2018, 1, 11).and_hms_milli(12, 0, 0, 154);
assert_eq!(dt.round_subsecs(2).nanosecond(), 150_000_000);
assert_eq!(dt.round_subsecs(1).nanosecond(), 200_000_000);fn trunc_subsecs(self, digits: u16) -> Self
fn trunc_subsecs(self, digits: u16) -> Self
Return a copy truncated to the specified number of subsecond digits. With 9 or more digits, self is returned unmodified.
Example
let dt = Utc.ymd(2018, 1, 11).and_hms_milli(12, 0, 0, 154);
assert_eq!(dt.trunc_subsecs(2).nanosecond(), 150_000_000);
assert_eq!(dt.trunc_subsecs(1).nanosecond(), 100_000_000);