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]
When you change this to true, you may need to add more tests.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53141 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* test/ruby: use better assertions instead of mere assert.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44173 b2dd03c8-39d4-4d8f-98ff-823fe69b080e