AMDG Maarten Kronenburg wrote:
In my opinion an unsigned integer is a, works like a and can be substituted as an integer, and so is a modular integer, and as far as I'm concerned also an allocated integer. This is why I choose for derivation, and then with the base pointer to derived object (as quoted above) to runtime polymorphism.
I strongly disagree. 1) An unsigned integer only works like an integer for non-mutating operations. If clients take parameters of const integer&, sure, unsigned_integer will work fine in this context. Treating non-const integers polymorphically is a very bad idea, though. Code that does so has to be very carefully designed to make sure that it can handle all the combinations. If you have to use inheritance, make both integer and unsigned_integer inherit from a common base. 2) I would expect an integer class to be a value object. virtual functions don't play well with value objects, because to prevent slicing, everything has to be held by pointer. 3) unsigned_integer + unsigned_integer should return an unsigned_integer. There is no way for the result to be negative. This is even more glaring for modular_integer
And in my opinion an integer is not a container, so I see no reason to use templates.
??? In Christ, Steven Watanabe