Inheritance Best Practice? (custom number classes)

[alcaz0r]

I am currently working on creating my own classes to deal with numbers. My motivation is two-fold: I use Matlab a lot as a student, and I would like to have a lot of that functionality in C++. Also, I really want to learn how to use class inheritance to the fullest.

My general idea is to create a basic Number class with virtual functions, then wrap each number type in a custom class which will derive from Number. This way, I can write functions which take Numbers.

Chances are, I'm going about this completely backwards, and there are much easier, more robust, and generally better ways to do this!

First, I have defined an enumeration NumberType, each Number has one of these guys.

Now, lets look at the definition of Number, in particular, the equality operator.

class Number
{
protected:
	Number(NumberType t) : type(t) {} // NumberType is an enumeration
	
public:
	virtual ~Number(void) {}

	// virtual equality operator
	friend bool operator== (Number &n1, Number &n2) { return n1.isEqual(n2); }
	virtual bool isEqual(Number &n) { return false; }
	const NumberType type;
};

Now, so far I only have Bdouble and Bint, so please take a look at how I handle Bdouble's isEqual function.

bool Bdouble::isEqual(Number &n) 
{ 
	switch (n.type)
	{
	case NumberType::Bdouble: {
		Bdouble *nPtr = (Bdouble*)&n;
		return Value ==Ptr->Value;
		}
	case NumberType::Bint: {
		Bint *nPtr = (Bint*)&n;
		return Value == (int)*nPtr; // int () typecast defined in Bint
		}
	}
}

Now, I'm realizing that I will need a similar case structure for Bint. Also, every time I add a function, (and for Matlab level functionality I will need to add a LOT), I will be dealing with such case structures. Are there better ways to make classes deriving from the same base class play well together? Would a different approach altogether make sense in this case?

Any advice will be appreciated, thank you!

*edit: make some syntactical corrections to the code, and fixed where i had pasted the wrong function

[alcaz0r]

Perhaps I should add that eventually I would like to add classes for Complex, Vector and Matrix, which all would derive from Number. Then the inputs and outputs to functions like operator+ could return scalar or vector or matrix values depending on the the operands.