Implement Complex#<=>

Implement Complex#<=> so that it is usable as an argument when
calling <=> on objects of other classes (since #coerce will coerce
such numbers to Complex).  If the complex number has a zero imaginary
part, and the other argument is a real number (or complex number with
zero imaginary part), return -1, 0, or 1.  Otherwise, return nil,
indicating the objects are not comparable.

Fixes [Bug #15857]

1 files changed, 7 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index 0f612533ff..ef5b30151b 100644
--- a/NEWS
+++ b/NEWS
@@ -62,6 +62,13 @@ sufficient information, see the ChangeLog file or Redmine
 
 === Core classes updates (outstanding ones only)
 
+Complex::
+
+  New method::
+
+    * Added Complex#<=>. So 0 <=> 0i will not raise NoMethodError.
+      [Bug #15857]
+
 Enumerable::
 
   New method::