* lib/cmath.rb (CMath.cbrt): returns the principal value of the cube

  root of the argument.  fix #3676
* test/test_cmath.rb (test_cbrt_returns_principal_value_of_cube_root):
  test for the above change.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32047 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 6 deletions

diff --git a/lib/cmath.rb b/lib/cmath.rb
index 24a0e70f9c..4751f6c4a1 100644
--- a/lib/cmath.rb
+++ b/lib/cmath.rb
@@ -122,13 +122,9 @@ module CMath
   end
 
   ##
-  # returns the cube root of +z+
+  # returns the principal value of the cube root of +z+
   def cbrt(z)
-    if z.real?
-      cbrt!(z)
-    else
-      Complex(z) ** (1.0/3)
-    end
+    Complex(z) ** (1.0/3)
   end
 
   ##