pub fn duration_since(&self, earlier: &Self) -> Option<Duration> {
        if self < earlier {
            None
        } else {
            (self.as_nanos() - earlier.as_nanos())
                .try_into()
                .ok()
                .map(Duration::from_nanos)
        }
    }
/// The amount of time elapsed from another instant to this one.
///
/// Returns `None` if `earlier` is later than self.
The amount of time elapsed from another instant to this one.
Returns `None` if `earlier` is later than self.
The amount of time elapsed from another instant to this one . Returns ` None ` if ` earlier ` is later than self .
pub fn duration_since(&self, earlier: &Self) -> Option<Duration> {
        if self < earlier {
            None
        } else {
            (self.as_nanos() - earlier.as_nanos())
                .try_into()
                .ok()
                .map(Duration::from_nanos)
        }
    }
pub fn duration_since ( & self , earlier : & Self ) -> Option < Duration > { if self < earlier { None } else { ( self . as_nanos ( ) - earlier . as_nanos ( ) ) . try_into ( ) . ok ( ) . map ( Duration :: from_nanos ) } }
The amount of time elapsed from another instant to this one.
The amount of time elapsed from another instant to this one .
&self
earlier
&Self
&self
earlier
&Self