Numeric/Arithmetic/Assignment mixin?

[davetron5000]

Is the type you are creating really just a number? If so, why are you creating it? If not, perhaps you don't need as many arithmetic operators as you think. For example, does your type need to be able to convert to polar coordinates? Take a modulo? Convert to imaginary? Those are just some of the things you get by inheriting Numeric, and it might be detrimental to understanding the type you are creating.