inline std::ostream& operator<<(std::ostream& stream, const Duration& duration_)
{
// Output the duration in full double precision and save the old precision.
std::streamsize precision =
stream.precision(std::numeric_limits<double>::digits10);
// Parse the duration as the sign and the absolute value.
Duration duration = duration_;
if (duration_ < Duration::zero()) {
stream << "-";
// Duration::min() may not be representable as a positive Duration.
if (duration_ == Duration::min()) {
duration = Duration::max();
} else {
duration = duration_ * -1;
}
}
// First determine which bucket of time unit the duration falls into
// then check whether the duration can be represented as a whole
// number with this time unit or a smaller one.
// e.g. 1.42857142857143weeks falls into the 'Weeks' bucket but
// reads better with a smaller unit: '10days'. So we use 'days'
// instead of 'weeks' to output the duration.
int64_t nanoseconds = duration.ns();
if (duration < Microseconds(1)) {
stream << duration.ns() << Nanoseconds::units();
} else if (duration < Milliseconds(1)) {
if (nanoseconds % Duration::MICROSECONDS != 0) {
// We can't get a whole number using this unit but we can at
// one level down.
stream << duration.ns() << Nanoseconds::units();
} else {
stream << duration.us() << Microseconds::units();
}
} else if (duration < Seconds(1)) {
if (nanoseconds % Duration::MILLISECONDS != 0 &&
nanoseconds % Duration::MICROSECONDS == 0) {
stream << duration.us() << Microseconds::units();
} else {
stream << duration.ms() << Milliseconds::units();
}
} else if (duration < Minutes(1)) {
if (nanoseconds % Duration::SECONDS != 0 &&
nanoseconds % Duration::MILLISECONDS == 0) {
stream << duration.ms() << Milliseconds::units();
} else {
stream << duration.secs() << Seconds::units();
}
} else if (duration < Hours(1)) {
if (nanoseconds % Duration::MINUTES != 0 &&
nanoseconds % Duration::SECONDS == 0) {
stream << duration.secs() << Seconds::units();
} else {
stream << duration.mins() << Minutes::units();
}
} else if (duration < Days(1)) {
if (nanoseconds % Duration::HOURS != 0 &&
nanoseconds % Duration::MINUTES == 0) {
stream << duration.mins() << Minutes::units();
} else {
stream << duration.hrs() << Hours::units();
}
} else if (duration < Weeks(1)) {
if (nanoseconds % Duration::DAYS != 0 &&
nanoseconds % Duration::HOURS == 0) {
stream << duration.hrs() << Hours::units();
} else {
stream << duration.days() << Days::units();
}
} else {
if (nanoseconds % Duration::WEEKS != 0 &&
nanoseconds % Duration::DAYS == 0) {
stream << duration.days() << Days::units();
} else {
stream << duration.weeks() << Weeks::units();
}
}
// Return the stream to original formatting state.
stream.precision(precision);
return stream;
}
