C++ with interfaces

I have written and posted a C++ language extension (HeronFront) which
demonstrates how interfaces can significantly outperform designs that use
multiple inheritance of abstract base classes.

For example the NaiveInt class in the following example in C++ :
http://www.heron-language.com/abc-example.html when rewritten using
interfaces in HeronFront (
http://www.heron-language.com/hfront-example.html ) takes 1/8th the size and
runs signficantly faster. The only drawback are that interface references
take two pointers instead of one pointer like to an abstract base class.

The code and examples are available for download at
http://www.heron-language.com/heronfront.html . I would appreciate any and
all feedback.

Thanks in advance.

Christopher Diggins
http://www.cdiggins.com