pub fn parse_optional_millis_to_nanos(millis: i64) -> Result<Option<UnixNanos>>Expand description
Converts a signed Unix millisecond timestamp into [UnixNanos].
Negative inputs are mapped to Ok(None) so callers can model fields
where the wire uses -1 (or any negative sentinel) as “absent”. Fields
that overload 0 with a separate meaning (e.g. 0 for IOC on
OrderInfo::order_expiry) must apply that interpretation at the call
site; this helper treats 0 as a literal Unix epoch timestamp.
§Errors
Returns an error if a non-negative millis overflows when scaled to
nanoseconds.