Implement "isa" for classdef objects. * ov.h (octave_value::is_instance_of): New method. * ov-base.h (octave_base_value::is_instance_of): Likewise. * ov-class.h (octave_class::is_instance_of): New method declaration. * ov-class.cc (octave_class::is_instance_of): Implement it with find_parent_class. * ov-classdef.h (octave_classdef::is_instance_of): New method declaration. * ov-classdef.cc (octave_classdef::is_instance_of): Implement it with lookup_class and is_superclass.

--- a/libinterp/octave-value/ov-class.h	Sat Sep 20 06:31:27 2014 -0700
+++ b/libinterp/octave-value/ov-class.h	Sat Sep 20 12:43:25 2014 -0400
@@ -167,6 +167,8 @@
 
   octave_base_value *unique_parent_class (const std::string&);
 
+  bool is_instance_of (const std::string&) const;
+
   string_vector all_strings (bool pad) const;
 
   void print (std::ostream& os, bool pr_as_read_syntax = false);