diff options
Diffstat (limited to 'Lib/test/test_float.py')
| -rw-r--r-- | Lib/test/test_float.py | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py index fb47db8..1c74c96 100644 --- a/Lib/test/test_float.py +++ b/Lib/test/test_float.py @@ -81,6 +81,7 @@ class UnknownFormatTestCase(unittest.TestCase): # on an IEEE platform, all we guarantee is that bit patterns # representing infinities or NaNs do not raise an exception; all else # is accident (today). +# let's also try to guarantee that -0.0 and 0.0 don't get confused. class IEEEFormatTestCase(unittest.TestCase): if float.__getformat__("double").startswith("IEEE"): @@ -99,6 +100,20 @@ class IEEEFormatTestCase(unittest.TestCase): ('<f', LE_FLOAT_NAN)]: struct.unpack(fmt, data) + if float.__getformat__("double").startswith("IEEE"): + def test_negative_zero(self): + import math + def pos_pos(): + return 0.0, math.atan2(0.0, -1) + def pos_neg(): + return 0.0, math.atan2(-0.0, -1) + def neg_pos(): + return -0.0, math.atan2(0.0, -1) + def neg_neg(): + return -0.0, math.atan2(-0.0, -1) + self.assertEquals(pos_pos(), neg_pos()) + self.assertEquals(pos_neg(), neg_neg()) + def test_main(): test_support.run_unittest( |