change negativity check

Author: newpavlov

src/libcore/time.rs

@@ -517,16 +517,16 @@ impl Mul<f64> for Duration {
 
  fn mul(self, rhs: f64) -> Duration {
  const NPS: f64 = NANOS_PER_SEC as f64;
- if rhs.is_sign_negative() {
- panic!("duration can not be multiplied by negative float");
- }
  let nanos_f64 = rhs * (NPS * (self.secs as f64) + (self.nanos as f64));
  if !nanos_f64.is_finite() {
  panic!("got non-finite value when multiplying duration by float");
  }
  if nanos_f64 > MAX_NANOS_F64 {
  panic!("overflow when multiplying duration by float");
- };
+ }
+ if nanos_f64 < 0.0 {
+ panic!("underflow when multiplying duration by float");
+ }
  let nanos_u128 = nanos_f64 as u128;
  Duration {
  secs: (nanos_u128 / (NANOS_PER_SEC as u128)) as u64,
@@ -541,16 +541,16 @@ impl Mul<Duration> for f64 {
 
  fn mul(self, rhs: Duration) -> Duration {
  const NPS: f64 = NANOS_PER_SEC as f64;
- if self.is_sign_negative() {
- panic!("duration can not be multiplied by negative float");
- }
  let nanos_f64 = self * (NPS * (rhs.secs as f64) + (rhs.nanos as f64));
  if !nanos_f64.is_finite() {
  panic!("got non-finite value when multiplying float by duration");
  }
  if nanos_f64 > MAX_NANOS_F64 {
  panic!("overflow when multiplying float by duration");
- };
+ }
+ if nanos_f64 < 0.0 {
+ panic!("underflow when multiplying float by duration");
+ }
  let nanos_u128 = nanos_f64 as u128;
  Duration {
  secs: (nanos_u128 / (NANOS_PER_SEC as u128)) as u64,
@@ -588,16 +588,16 @@ impl Div<f64> for Duration {
 
  fn div(self, rhs: f64) -> Duration {
  const NPS: f64 = NANOS_PER_SEC as f64;
- if rhs.is_sign_negative() {
- panic!("duration can not be divided by negative float");
- }
  let nanos_f64 = (NPS * (self.secs as f64) + (self.nanos as f64)) / rhs;
  if !nanos_f64.is_finite() {
  panic!("got non-finite value when dividing duration by float");
  }
  if nanos_f64 > MAX_NANOS_F64 {
  panic!("overflow when dividing duration by float");
- };
+ }
+ if nanos_f64 < 0.0 {
+ panic!("underflow when multiplying duration by float");
+ }
  let nanos_u128 = nanos_f64 as u128;
  Duration {
  secs: (nanos_u128 / (NANOS_PER_SEC as u128)) as u64,