Dear Marco, On Thu, 24 Feb 2005 mdias@ift.unesp.br wrote:
Thanks Chris, I modified and compiled ok. but subs() make nothing. I have to delare a new subs() function? Is there in source a example?
Well, you made covdiff inherit from indexed. Indexed already has a .subs() method that comes from the type container that it is based on, so you are actually subsing in the underlying indexed object. You could, of course, add your own .subs()-method, but before you do so, you should ask yourself wheter inheriting from indexed is really what you want to do. If you want to inherit from indexed, why do you need to define your own member variables index and arg? Indexed already has the data structures to hold these. Also, making these public looks like a bad idea. Furthermore, why does this class have a member index and besides that a member new_index? If I were to write such a class, my first inclination would be to indeed try to make it a child class of indexed, but then to simply hold an integer that would hold, say 3, if the indexed object has 3 indices and further indices indicate differentiation. This would behave more or less as expected with respect to summations conventions and so on. Best wishes, Chris