Refactored using Method#owner.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58245 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/pp.rb

@@ -311,7 +311,7 @@ class PP < PrettyPrint
         inspect_method = method_method.call(:inspect)
       rescue NameError
       end
-      if inspect_method && /\(Kernel\)#/ !~ inspect_method.inspect
+      if inspect_method && inspect_method.owner != Kernel
         q.text self.inspect
       elsif !inspect_method && self.respond_to?(:inspect)
         q.text self.inspect
@@ -345,7 +345,7 @@ class PP < PrettyPrint
     # However, doing this requires that every class that #inspect is called on
     # implement #pretty_print, or a RuntimeError will be raised.
     def pretty_print_inspect
-      if /\(PP::ObjectMixin\)#/ =~ Object.instance_method(:method).bind(self).call(:pretty_print).inspect
+      if Object.instance_method(:method).bind(self).call(:pretty_print).owner == PP::ObjectMixin
         raise "pretty_print is not overridden for #{self.class}"
       end
       PP.singleline_pp(self, ''.dup)